Conflict coltan from Congo linked to Sony, Microsoft, Nvidia supply chains

Coltan smuggled from mines controlled by the M23 armed group in the Democratic Republic of Congo has entered supply chains serving major technology and automotive companies, exposing weaknesses in industry efforts to keep conflict minerals out of consumer products, a new report shows.

London-based investigative group Global Witness found that five of Rwanda’s seven largest coltan exporters purchased material originating from the Rubaya mining area in North Kivu, where M23 has controlled operations for the past two years.

The report said the mineral, which is used in smartphones, computers and other electronics, is likely to have reached supply chains connected to Sony, Microsoft, Amazon, LG Display, Ericsson, Toyota, Nvidia and Vodafone.

The investigation covered the period from 2023 through September 2025 and drew on trade data, field research and interviews with more than 70 sources.

“Behind our everyday tech lies a supply chain tainted by violence, exploitation, and human suffering,” Alex Kopp, senior policy and advocacy advisor at Global Witness, said. “The companies behind our phones, computers and cars haven’t been able or willing to clean up their supply chains.”

The findings raise fresh questions about the effectiveness of mineral traceability and due diligence programs that companies rely on to certify responsible sourcing.

Global Witness alleged that the ITSCI traceability system has been used to launder significant volumes of smuggled coltan and said conflict-linked material may also have entered the Better Mining system.

The group further argued that audits conducted under the Responsible Minerals Initiative (RMI) failed to identify substantial quantities of conflict coltan moving through smelter supply chains.

Pushback

Several companies and organizations disputed or challenged aspects of the findings. Toyota said it aims to procure conflict-free minerals through supplier due diligence, while Sony said it expects suppliers to comply with its sourcing standards.

Ericsson said the smelters identified by Global Witness were compliant with Responsible Minerals Initiative requirements and that it would review the cases cited. Traxys denied sourcing conflict minerals, Better Mining denied tagging conflict-affected coltan, and ITSCI said its system remains active and functional. Nvidia, Amazon, Microsoft, Vodafone and LG Display did not respond to requests for comment, according to Global Witness.

The investigation comes as governments and manufacturers face growing pressure to secure critical mineral supply chains. Rubaya accounts for roughly 15% of global coltan production, making the region strategically important to the electronics industry.

The report concludes that stronger enforcement, corporate accountability and sanctions against those financing or benefiting from the conflict are needed to prevent minerals linked to human rights abuses from reaching international markets.