Announcement PDF Page | 1 16 December 2025 Accompanying video: click here Paris Silver DFS Update: Pit Optimisation and Metallurgical Improvements Highlight Potential to Increase Silver Recovery and Mineable Inventory at the Paris Silver Project Highlights • ~6% increase in silver recovery achieved by reducing the primary grind size to 53 microns in the dominant material type. • Revised pit optimisation incorporating updated cost inputs and a higher silver price assumption materially reduces the economic cut-off grade and improves strip ratio, highlighting the potential to increase the mineable inventory. • These changes form the new Definitive Feasibility Study (DFS) design basis, which is now being incorporated into detailed engineering and cost estimation work, on track for delivery in H1 2026. Managing Director’s Comment Investigator Resources Managing Director, Lachlan Wallace, said: “The Paris DFS continues to mature through a disciplined and transparent process. By reporting key technical outcomes as individual workstreams advance, we are providing shareholders with clear visibility on how the study is progressively strengthening the project design and development framework. In a silver price environment that is at, or near, record levels, it is particularly encouraging to see the technical studies responding as expected. Pit optimisation work indicates the potential to capture additional mineralised material within the mine plan through a lower economic cut-off grade, while concurrent metallurgical testwork has delivered higher silver recoveries through a finer grind. Together, these outcomes reinforce the leverage of the Paris Silver Project to silver price and the quality of the underlying resource. The pit optimisation results are especially important, demonstrating the inherent strength of the Paris resource and its sensitivity to silver price. At the optimisation level, the combination of lower cut-off grades and a materially reduced strip ratio highlights the opportunity to develop a more efficient and robust mining framework as the study progresses. As the DFS advances into detailed scheduling, process design and cost finalisation, our focus is on translating these improved technical parameters into a practical, staged and finance- ready development plan. The Company remains firmly on track to deliver the Paris Silver Project DFS in the first half of 2026. A short video update is available here.” ASX Release – Investigator Page | 2 Pit Optimisation Study Important Notice: The information in this section relates solely to a conceptual pit optimisation study completed as part of ongoing Definitive Feasibility Study work for the Paris Silver Project in South Australia. The pit optimisation is a technical planning and sensitivity tool used to inform potential pit geometries, staging options and mine design considerations under a defined set of assumptions. The results of the optimisation do not constitute, and should not be interpreted as, a Production Target, Ore Reserve, Mineral Resource upgrade, or forecast of production, costs or economic outcomes. The optimisation outputs are preliminary in nature and have not been subject to the application of all modifying factors required under the JORC Code, including but not limited to mining dilution and recovery, detailed mine design, scheduling, geotechnical constraints, metallurgical recoveries, infrastructure layout, permitting, environmental approvals, and economic evaluation. Accordingly, there is no certainty that the outcomes of the optimisation will be realised. Final pit designs, mining inventories and production schedules will be determined through the DFS process and will incorporate appropriate technical, operational, regulatory and economic modifying factors prior to any consideration of a Production Target or Ore Reserve. The Company is providing this information to keep the market informed of material technical progress in the Paris Silver Project as Definitive Feasibility Study work advances. The pit optimisation results highlight the sensitivity of mine planning parameters—including cut-off grade, strip ratio and mineable inventory— to updated cost inputs and prevailing commodity price conditions. This information is disclosed to provide transparency around the direction and robustness of the ongoing study work, rather than to pre-empt or substitute for the outcomes of the DFS or any future declaration of a Production Target or Ore Reserve. Mineable inventory figures referenced in this section are derived from optimisation outputs only and do not represent a mine design, Production Target or Ore Reserve. The Company has completed a revised pit optimisation incorporating a higher silver price assumption, updated operating cost inputs, and revised slope parameters informed by the recent geotechnical drilling program. A silver price of A$70/oz was adopted for optimisation purposes, materially below the current spot price of approximately A$95/oz. At this price, and using updated cost assumptions, the estimated economic cut-off grade reduces materially from 43.5 g/t Ag in the 2021 Pre-Feasibility Study (PFS) to a range of 22– 27 g/t Ag, depending on host rock type. This reflects materially improved project economics at the optimisation level under current market conditions. The lower cut-off grade increases contained silver within the optimised pit shell by approximately 13 Moz relative to the PFS. In addition, the strip ratio improves significantly, reducing from 8.4:1 in the PFS to approximately 4.2:1 in the new optimisation. It is important to note that the final design will vary from the optimisation and it may not be practical to capture all of the optimised silver ounces owing to modifying factors that will be applied to the design. This is particularly relevant in the northern and southern extremities of the optimal pit design which incorporate lower grade mineralisation at the higher prices (see Figure 1). Further investigation of the viability of these areas is underway as part of the pit design process. ASX Release – Investigator Page | 3 Figure 1 Pit Optimisation Pit Shell 26 (grey) compared to current pit design (yellow and red). A comparison to the 2021 PFS of key inputs and results are summarised in Table 1. Table 1 Paris Silver Pit Optimisation – PFS to December 2025 Study Key assumptions PFS 2021# Dec-25 Optimisation Silver price A$/oz 34.3 70 Cut-off grade g/t Ag 43.5 22 to 27(1) Overall slope angle degrees 45 38 to 55(2) Mining Operating Cost A$/t mined 2.51 5.97 Processing Operating Cost A$/t processed 30.76 34 to 38(1) Average Silver Recovery % 75.7 67 to 86(1) Target mining rate Mtpa 2 1.5 Discount Rate % 10 10 Key results PFS Dec-25 Optimisation Waste Mt 72 77 Silver Mineralisation (insitu) Mt / Moz 8.6 / 35 18 / 48 Strip Ratio waste : silver mineralisation 8.4 4.2 Note 1 - ranges for processing costs and recovery are dependent on type of silver mineralisation and impact the respective cut-off grade Note 2 – slope angle is determined by local geotechnical conditions The primary driver of this outcome is the silver price. Due to the steep tonnage curve at the cut-off grade (Figure 2), relatively small changes in economic assumptions result in a meaningful increase in mineable inventory. Conversion of mineralised waste to mill feed via further improvements in economics, in particular, silver price and silver recovery, has potential to further reduce the cut-off grade and strip ratio. __________________________________ # ASX 30th November 2021 – Paris DFS Delivers Outstanding Results Higher price assumption driving pit to expand north and south. Investigation will be undertaken to determine the viability and geological confidence in these areas. ASX Release – Investigator Page | 4 Figure 2 Paris Silver Project: Grade–Tonnage curve, Global Mineral Resource Estimate > 0mRL1 Figure 3 and 4 highlight the optimised Pit Shells that will be used to guide the staged pit designs (blue) as follows: • Pit Shell 6 is proposed as a starter pit to bring forward early cash generation and minimise initial working capital requirements. • Pit Shell 20 represents the largest pit shell prior to a material increase in strip ratio (refer Figure 4). This shell is expected to inform the Stage 2 pit design, allowing value to be realised ahead of a larger cut-back. The sequencing prioritises higher-grade material in the early stages, which improves discounted project value and provides a more resilient early-stage cash-flow profile during the initial years of operation. This profile is expected to support project finance discussions by reducing early-stage risk and improving financeability, which may assist in achieving more efficient financing outcomes. Notably, this pit shell is also broadly consistent with optimisation outcomes at lower silver price assumptions (A$58/oz), demonstrating robustness across a range of price scenarios, including lower prices. • Pit Shell 26 returns the highest theoretical value on a discounted basis and will be used to guide the ultimate pit design, subject to incorporation of appropriate modifying factors through the DFS. The larger cut-back associated with Pit Shell 26 is expected to be deferred until approximately Year 5 of the operation, providing flexibility in mine sequencing and capital allocation. This staged approach preserves optionality, enabling the Company to assess the timing and scale of the 1 ASX 5th July 2023 – Paris Mineral Resource Estimate Update Tonnage curve (blue) is steep around cut-off grade, providing opportunity to materially increase minable inventory with relatively minor changes to cut-off ASX Release – Investigator Page | 5 ultimate pit expansion in the context of prevailing market conditions, operating performance and capital availability. Figure 3 Paris Silver Pit Optimisation – recovered silver in different pit shells Figure 4 Paris Silver Pit Optimisation – cumulative strip Ratio in different pit shells ASX Release – Investigator Page | 6 How to interpret Figure 3. Although the graph is a standard output from the optimisation, this explanation is considered necessary to ensure that it is interpreted correctly. • The Pit Shells in Figure 3 change in size (represented as silver oz recovered) based on a Revenue Factor (RF). The RF at Pit Shell 26 is 1, representing the assumed price in the optimisation (A$70/oz) and generates the highest theoretical NPV. • A series of larger and smaller Pit Shells are created by using RF higher and lower than 1 respectively. These are shown as yellow columns in Figure 3. • Although the Pit Shells are based on different RF, the NPV curve applies a RF of 1 (A$70/oz) to all NPV calculations. Importantly, the optimised pit does not significantly change in size due to a wide range of price assumptions. Pit 60 represents the Pit Shell under a Revenue Factor of 1.97 (A$138.12/oz), almost double the price assumed in the Pit Optimisation. Figure 3 highlights that even under such a materially higher assumed price, the optimal recovered ounces would only increase by around 6Moz (at a fixed cut-off grade). This indicates that the pit parameters assumed in the optimisation drive a pit that maximises resource extraction (ie, the optimisation is Resource constrained) and that the project design will not change materially, and will perform, under a range of future price scenarios. Such design stability is a valuable attribute in the rapidly changing silver price environment, as it enables the design to be finalised and proceed through permitting and funding with confidence that there will not be material changes. The production schedule is being structured to prioritise higher-grade feed in the early years of operation. Material identified at lower cut-off grades through the optimisation is expected to be stockpiled for later processing, preserving a strong early cash-flow profile and supporting financing and payback objectives. Overall, the optimisation, and the ongoing design and scheduling, is expected to materially improve project economics through higher payable metal and a lower strip ratio, without compromising the quality or bankability of the early mine plan. Metallurgical Review Comprehensive metallurgical testwork completed by Bureau Veritas to support the Paris Silver Project DFS has been completed and independently reviewed. The program included mineral characterisation, mineralogy (QEMSCAN and XRD), comminution testing, grind size optimisation, agitated cyanide leaching and CIL trials, flocculant and thickening assessments, and vendor filtration studies. Fifteen composite samples comprising four geometallurgically defined composites reflective of the two main metallurgical domains, together with eleven variability samples, were evaluated. Results confirm that the Paris mineralisation is amenable to conventional cyanidation with consistently high silver recoveries across the dominant lithological domains. Over a range of silver head grades, recoveries improved markedly with finer grind sizes. For the composite samples representing four metallurgical domains, standard leach testing demonstrated an average 6.2% increase in silver recovery when grind size was reduced from 75 µm to 53 µm, with recoveries exceeding 90% Ag in the higher-grade breccia units. A bulk composite leach achieved ~79.5% Ag recovery at P80 45 µm, confirming scalability. The cyanide leach test results are summarised in Table 2. The domains ASX Release – Investigator Page | 7 represent the BT and BTM domains which make up 74% of the mineralisation within the existing pit design. Figure 5 highlights that the composite test samples were collected from a wide range of areas and are considered representative of BT and BTM feed. Table 2 Cyanide Leach Test Summary - Ag Extraction for Various P80 Grind Sizes Sample 106 microns 75 microns 53 microns 45 microns Extraction % Extraction % Extraction % Extraction % D, C1 76.9 66.7 79 78.7 D, C2 63.6 62.4 65.5 69.4 D, C3 69.7 67.3 75.8 78.4 D, C4 97.6 97.4 98.3 96.0 Bulk leach - - - 79.5 D, Av % - 73.5 79.7 80.4 Uplift % - - 6.2 7.0 Figure 5 Location of composite samples used in the metallurgical testwork The recent pit optimisation study (refer this announcement) is indicating that the pit may push deeper, which potentially brings more dolomite hosted silver mineralisation (DOL) into the mineable inventory. Historically the DOL has returned excellent recovery, including 89% at 53 µm, but only made up a relatively small proportion, approximately 9%, of the PFS inventory in 2021. Given the relative higher recovery of DOL, an increase in the proportion of DOL within the mine plan would result in a higher average recovery. Dolomite may increase in mine plan as pit pushes deeper, increasing overall recovery ASX Release – Investigator Page | 8 Comminution testing indicated moderate hardness (up to Bond Ball Work Index ~16 kWh/t), suitable for a standard crushing and milling circuit. Thickening and filtration trials confirmed favourable settling and dewatering characteristics for conventional tailings handling. Zinc-precipitation tests validated effective silver recovery via Merrill–Crowe processing. Overall, the testwork confirms a robust and conventional processing flow sheet, with improved recoveries and operating confidence, providing strong metallurgical support for the updated DFS design basis. Updated Design Basis The outcomes of the metallurgical review and pit optimisation now form the updated DFS design basis and are being incorporated into detailed engineering, mine scheduling and cost estimation. With these key inputs defined, Investigator is progressing into the final phase of technical and economic evaluation for the Paris Silver Project. The next phase of work will focus on: • completion of detailed mine scheduling to optimise grade delivery and cashflow profile; • finalisation of process plant design, including equipment selection and engineering design; • development of operating and capital cost estimates based on the updated design; and • integration of revised mining, processing and cost inputs into the project financial model. Process design and cost estimation work will be completed during January, following which the updated financial model will be prepared to support the Definitive Feasibility Study. The DFS is expected to be released in H1 2026, providing a fully integrated technical and economic assessment of the Paris Silver Project under the updated design parameters. For and on behalf of the board. Lachlan Wallace Managing Director For further information, please contact: Lachlan Wallace Managing Director + 61 (0) 8 7325 222 lwallace@investres.com.au ASX Release – Investigator Page | 9 About Investigator Resources Investigator’s 100% owned Paris Silver Project is located 70km north of the rural township of Kimba on South Australia’s Eyre Peninsula. The Paris Silver Project, with a JORC 2012 resource of 24Mt @ 73g/t silver and 0.41% lead for 57Mozs silver and 99kt lead, is a shallow high-grade silver deposit amenable to open pit mining, providing outstanding exposure to a metal with strong commodity, renewable energy and manufacturing demand. With positive outcomes of the Paris Project’s Pre-Feasibility Study as reported in November 2021, the company is undertaking the work required to complete a Definitive Feasibility Study, whilst continuing to progress exploration proximal to Paris and across adjacent significant ground holdings within South Australia. Competent Person Statement The information in this release relating to exploration results is based on information compiled by Mr. Jason Murray who is a full-time employee of the company. Mr. Murray is a member of the Australian Institute of Geoscientists. Mr. Murray has sufficient experience of relevance to the styles of mineralisation and the types of deposits under consideration, and to the activities undertaken, to qualify as a Competent Person as defined in the 2012 Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves. Mr. Murray consents to the inclusion in this report of the matters based on information in the form and context in which it appears. The information in this release that relates to Mineral Resources Estimates at the Paris Silver Project is extracted from the release titled “Paris Mineral Resource Estimate Update” dated 5 July 2023 and is available to view on the Company’s website www.investres.com.au. The Company confirms that it is not aware of any new information or data that materially affects the information included in the original market announcement and that all material assumptions and technical parameters underpinning the estimates in the relevant market announcement continue to apply and have not materially changed. The company confirms that the form and context in which the Competent Person’s findings are presented have not been materially modified from the original market announcement. The information in this announcement relating to metallurgical results is based on information compiled by Matthew Leske who is a consultant to the company. Mr Leske is a member of the Australian Institute of Mining and Metallurgy (AusIMM). Mr Leske has sufficient experience of relevance to the commodities and process flow sheets under consideration, and to the activities undertaken, to qualify as a Competent Person as defined in the 2012 Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves. Mr Leske consents to the inclusion in this report of the matters based on information in the form and context in which it appears. ASX Release – Investigator Page | 10 Paris Mineral Resource Estimate2 2023 Paris Silver Project Mineral Resource estimate (25g/t silver cut-off grade). (Note: Total values may differ due to minor rounding errors in the estimation process) 1,2 ASX announcement 5 July 2023 “Paris Mineral Resource Estimate Update”. The Company confirms that it is not aware of any new infor- mation or data that materially affects the information included in the original market announcement of 5 July 2023 and that all material assumptions and technical parameters underpinning the estimates in the relevant market announcement continue to apply and have not materially changed. The company confirms that the form and context in which the Competent Person’s findings are presented have not been materially modified from the original market announcement. ASX Release – Investigator Page | 11 Appendix 1: JORC Code, 2012 Edition – Table 1 The following section is provided to ensure compliance with the JORC (2012) requirements for the re- porting of test work presented in this ASX announcement. Section 1 Sampling Techniques and Data (Criteria in this section apply to all succeeding sections.) Criteria and JORC Code explana- tion Commentary Sampling techniques • Nature and quality of sampling (e.g. cut channels, random chips, or spe- cific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. • Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. • Aspects of the determination of min- eralisation that are Material to the Public Report. • 2024/2025 metallurgical sample material was obtained from PQ3 dia- mond core drilled for metallurgical testing in addition to a number of intervals drilled as part of geotechnical or resource drilling at Paris. • All metallurgical sample material was selected on the basis of its multi-element geometallurgical composition and presence of silver mineralisation at a grade that was representative of the Paris silver deposit average grade, including allowance for some dilution material where appropriate to simulate “mining conditions”. • 2024/2025 metallurgical testwork was focussed on primary geometal- lurgical domain variability testwork based on gangue material associa- tions in domains. • Sample media used in metallurgical test work was supplied to Bureau Veritas (BV) in individual 1m sample volumes with hole number and metre interval recorded. Subsequent compositing was undertaken by BV in accordance with consultant metallurgist guidelines. • Drill intervals had weight of sample recorded. Drilling techniques • Drill type (e.g. core, RC, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (e.g. core diameter, triple or standard tube, depth of diamond tails, face- sampling bit or other type, whether core is oriented and if so, by what method, etc). • Diamond drilling was PQ3 size and not oriented due to argillic altera- tion preventing usable orientation data. Drill sample recovery • Method of recording and assessing core and chip sample recoveries and results assessed. • Measures taken to maximise sam- ple recovery and ensure repre- sentative nature of the samples. • Whether a relationship exists be- tween sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. • Sample used for metallurgical testwork was selected based on repre- sentative silver content and of a number of gangue types for variability testwork in addition to composited bulk metallurgical testwork. • All material had been previously assessed for recovery and represent- ativeness as part of prior mineral resource estimation (s) and as such was selected on basis of gangue mineral variability and in order to ob- tain a composite grade that approximated the predicted grade when processing ore based on the 2021 Paris Prefeasibility Study and ac- companying metallurgical testwork. • Samples were selected based on their primary geometallurgical do- main ie “BT” – Breccia Transitional and “BTM” – Breccia Transitional Magnesium. • Priority focus was the BT domain which makes up approximately 55% of the mineralisation estimated in the deposit (2021). • Logging • Whether core and chip samples have been geologically and geotech- nically logged to a level of detail to • No additional logging of drilling occurred as part of this release on metallurgical outputs, with logging data from previous programs incor- porated in sample selection. • Sample selection and identification of gangue domains utilised data ASX Release – Investigator Page | 12 Criteria and JORC Code explana- tion Commentary support appropriate Mineral Re- source estimation, mining studies and metallurgical studies. • Whether logging is qualitative or quantitative in nature. Core (or cos- tean, channel, etc) photography. • The total length and percentage of the relevant intersections logged. from 200 XRD analyses across the deposit in addition to previous li- thology and multielement assay data, with domains predicted utilising a machine learning process with subsequent review and validation by IVR exploration manager. Sub-sampling techniques and sample preparation • If core, whether cut or sawn and whether quarter, half or all core taken. If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. For all sample types, the nature, quality and appropriateness of the sample preparation technique. Quality control procedures adopted for all sub-sampling stages to max- imise representivity of samples. • Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field dupli- cate/second-half sampling. • Whether sample sizes are appropri- ate to the grain size of the material being sampled. • Sample was provided in the form of unique metre intervals within holes as selected by the consultant metallurgist. • Composite sample information was supplied to the laboratory which identified unique composite ID’s in addition to relevant original sample ID’s which were to be combined in the compositing process to form the composite ID material. • Sub sampling of BT and BTM material used both geometallurgical do- main boundaries and gangue associations for intervals of mineralised DH material that was retained on site. BT and BTM domain material was dispatched to Bureau Veritas (BV) for composite selection and homogenisation. • Sample sizes for both domains are considered appropriate for test- work undertaken. Laboratory sample preparation • Subsampling techniques are undertaken in line with standard operat- ing practices in order to ensure no bias. • The nature, quality and appropriateness of the sampling technique is considered appropriate for the grainsize and type of mineralisation and confidence level being attributed to the results presented. Quality of assay data and labora- tory tests • The nature, quality and appropriate- ness of the assaying and laboratory procedures used and whether the technique is considered partial or to- tal. • For geophysical tools, spectrome- ters, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, cali- brations factors applied and their derivation, etc. • Nature of quality control procedures adopted (e.g. standards, blanks, du- plicates, external laboratory checks) and whether acceptable levels of ac- curacy (i.e. lack of bias) and preci- sion have been established. • A certified and accredited global laboratory (BV) was used for all as- says. • Head assay analysis was conducted on twelve samples in the BV an- alytical laboratory. A combination of methods to digest and analyse the samples were used, these include mixed acid digest, LECO and aqua regia, followed by Inductively Couple Plasma-Mass Spectrome- try (ICP-MS) and/or Inductively Couple PlasmaOptical Emission Spec- troscopy (ICP-OES). QA/QC Summary • Records of QA/QC techniques undertaken during each drilling pro- gram are retained by Investigator. • Certified reference standards including blanks, were randomly se- lected and inserted into the sampling sequence (1 in 25 samples) for all RC drilling where 1m sample intervals were assayed. • Field duplicate samples were routinely taken on every 20th sample for all RC drilling. • No significant analytical biases have been detected in the results pre- sented in prior exploration ASX releases for Paris that might impact the metallurgical results reported in this release. • Geochemical analysis of metallurgical sample composites were un- dertaken to confirm composition and suitability for metallurgical test- work and gross compositional similarity between 2017 and 2021 geo- metallurgical domains. ASX Release – Investigator Page | 13 Criteria and JORC Code explana- tion Commentary Verification of sampling and assaying • The verification of significant inter- sections by either independent or al- ternative company personnel. • The use of twinned holes. • Documentation of primary data, data entry procedures, data verification, data storage (physical and elec- tronic) protocols • Discuss any adjustment to assay data. • No reporting of new assay data outside of confirmation of geometal- lurgical grade and composition data and associated final testwork out- puts at various grind sizes and treatment processes. • Twinned holes for metallurgical testwork was not undertaken. • Records of sample intervals selected and utilised to produce repre- sentative metallurgical composite samples for testwork are retained by Investigator. Location of data points • Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. • Specification of the grid system used. • Quality and adequacy of topographic control. Collar co-ord