Global Witness has alleged that more than 2,000 tonnes of conflict coltan smuggled from eastern Democratic Republic of the Congo (DRC) has entered global supply chains via Rwanda, potentially reaching major electronics manufacturers and consumer brands despite international traceability and due diligence systems.

In a report published on June 10, titled Who buys Rwanda’s smuggled coltan?, the NGO said coltan originating from the Rubaya mining area in North Kivu – which accounts for around 15% of global tantalum supply – has become a key source of financing for the Rwanda-backed M23 rebel movement. Tantalum derived from coltan is used in capacitors found in smartphones, computers, vehicles and other electronic products.

While Rwanda is a major exporter of coltan, much of the region's tantalum production originates in eastern DRC. Listed companies with exposure to tantalum resources in the country include Tantalex Lithium Resources (CSE:TTX; FSE:DW8) and Power Metals Corp (TSXV:PWM), both active in the Manono lithium-tantalum district.

Globally, tantalum supply is dominated by a mix of African, Australian and Brazilian producers, with companies such as Pilbara Minerals (ASX:PLS) and AMG Critical Materials (AMS:AMG) playing important roles in downstream supply chains. Rising demand from electronics, electric vehicles and advanced manufacturing has increased the strategic importance of secure tantalum supplies in recent years.

Rubaya's coltan mines are among the most strategically important mineral assets in Africa, supplying around 15% of global tantalum demand. The area's thousands of artisanal miners form the backbone of the supply chain, but control of the mines has become a key objective in the conflict, with the United Nations and civil-society groups identifying coltan revenues as a major source of financing for M23 operations.

Global Witness said its year-long investigation found that at least five of the seven companies responsible for 85% of Rwanda’s coltan exports purchased material originating from conflict-affected areas of the DRC. The report alleges that the coltan was subsequently sold through intermediaries to smelters in China and Kazakhstan before entering international manufacturing supply chains.

Exporter	Coltan exported (tonnes)	Share of total volume (%)	Cumulative share (%)
East Group Minerals	1,333	29.7%	29.7%
Sunrise Metal Company	810	18.1%	47.8%
African Panther Resources	439	9.8%	57.6%
Tawotin	411	9.2%	66.8%
Kanzamin	362	8.1%	74.9%
Boss Mining Solution	306	6.8%	81.7%
Philbert Trading Minerals	155	3.5%	85.2%

Source: Global Witness analysis of customs data.
Note: Export volumes are based on customs data that may be incomplete; actual volumes may therefore be higher.

The organisation said conflict coltan may have ultimately reached supply chains linked to companies including Microsoft, Amazon, Apple, Sony, NVIDIA, Ericsson, LG Display, Toyota and Vodafone. The report does not allege that these companies knowingly sourced conflict minerals but argues that existing due diligence systems failed to prevent contaminated material from entering supply chains.

Buyer	Coltan purchased (tonnes)	Share of total volume (%)	Cumulative share (%)
Minterra	1,252	27.9%	27.9%
Halcyon	581	13.0%	40.9%
Traxys	567	12.6%	53.5%
East Rise Corporation	401	9.0%	62.5%
Novacore	296	6.6%	69.1%
Ningxia Orient Tantalum Industry Co.	234	5.2%	74.3%
Jiujiang Jinxin Non Ferrous Metals	211	4.7%	79.0%

Source: Global Witness analysis of customs data.
Note: Export volumes are based on customs data that may be incomplete; actual volumes may therefore be higher.

According to the report, M23 captured the Rubaya mining area in April 2024 and subsequently established a taxation system on production and trade. Global Witness cited UN estimates that the group generated approximately $800,000 per month from coltan-related taxes and fees. The report also alleges that traders pay levies both to M23 and to Rwandan authorities as minerals move across the border.

The NGO estimates that at least 1,400 tonnes of coltan were smuggled from the DRC into Rwanda within a year of M23's takeover of Rubaya, while UN experts described the resulting contamination of regional supply chains as the largest in a decade. It alleges that much of the material now crosses through the Goma border area under the observation of Rwandan officials.

Global Witness also criticised the International Tin Supply Chain Initiative (ITSCI), the dominant traceability scheme used for 3T minerals in Rwanda, arguing that it has been used to legitimise smuggled coltan rather than prevent conflict-linked material entering global markets. The report further claimed that alternative traceability programmes have also failed to identify risks associated with some exporters.

Rwanda's official coltan exports increased more than 2.5 times between 2021 and 2025, according to figures cited by the report. Coltan has become Rwanda's second-largest export earner after gold, generating growing scrutiny from UN experts and civil society organisations, which argue that export volumes exceed what domestic production alone can explain.

Global Witness called on companies to suspend purchases of coltan from Rwanda unless they can independently verify its origin, and urged the international community to impose sanctions on individuals and companies benefiting from conflict mineral trade and to make development assistance conditional on Rwanda ending support for M23. Rwanda has consistently denied supporting M23 and rejects allegations that it facilitates mineral smuggling from the DRC.