Coltan is one of those minerals that nobody knows, yet everybody needs. When processed, it creates tantalum – the metallic element vital for capacitors found in all sorts of advanced computing equipment.
Anything from large data centers to household gadgets relies on a steady supply of this obscure metal.
Yet, its supply chain is anything but transparent. A year-long investigation by the non-governmental organization Global Witness now alleges that the systems designed to ensure ethical sourcing have broken down.
“Behind our everyday tech lies a supply chain tainted by violence, exploitation, and human suffering,” Alex Kopp, senior policy and advocacy advisor, noted.
According to the report, smuggled “conflict coltan” originating from the Democratic Republic of the Congo (DRC) has infiltrated international supply chains and may have reached products associated with major technology companies, including NVIDIA Corp. (NVDA) and Microsoft Corp. (MSFT).
Despite years of investment programs to prevent illicit mineral extraction, research suggests that conflict-linked resources still flow into the global supply chain.
Tracking the Flows
The main region of interest is the North Kivu province. The area supplies approximately 15% of global tantalum demand, making it one of the world’s most strategically important coltan-producing regions. According to Global Witness, the mines have evolved into a major financial engine for the M23 rebel movement, which has been accused of widespread human rights abuses during its campaign in eastern Congo.
Following M23’s takeover, mineral trafficking dramatically increased. The UN data cited in the report estimates that at least 120 tons of coltan crossed into Rwanda monthly in 2024 – mostly through official border crossings.
The report argues that traceability systems to prevent this outcome are instead helping it. Programs such as ITSCI and Better Mining, both widely used in the minerals sector, are vulnerable to manipulation, as smuggled minerals are allegedly mixed with legitimately sourced Rwandan production before washing.
“The [exporting] company in Kigali comes and puts the tags on the coltan from Masisi, and thus it becomes Rwandan coltan,” one smuggler told Global Witness.
After leaving Rwanda, shipments move through ports in Tanzania and Kenya before reaching processing facilities. Global Witness identified eight major smelters handling significant volumes of Rwandan coltan between 2023 and 2025, most of them located in China, with others operating in Kazakhstan and Thailand.
The Corporate Response
Apple Inc. (AAPL), the firm that has been sued over conflict minerals before, took an aggressive stance. It told investigators that it instructed suppliers to halt purchases from both Rwanda and the DRC because it “was concerned that industry certification mechanisms could no longer perform the required due diligence.”
Ericsson (ERIC) replied that it works with the Responsible Minerals Initiative, while Toyota noted it proactively seeks conflict-free sourcing. Other companies chose not to engage publicly. NVIDIA, Microsoft, Amazon.com, Inc. (AMZN), Vodafone Group Plc (VOD), and LG did not respond to requests for comment.
To address these failures, Global Witness recommends an immediate suspension of Rwandan coltan, arguing that responsible sourcing under the current conditions is “almost impossible.”
The organization also advises stronger corporate accountability, stricter regulations, suspension of military exports to Rwanda, and sanctions against the M23 commanders and senior Rwandan officials responsible for the situation.
