Who Buys Rwanda's Smuggled Coltan? How Conflict Minerals From DRC End Up in Your Phone

Where have over 2,000 tonnes of smuggled conflict coltan gone? A year-long Global Witness investigation has followed the trail from the mines of eastern Congo to the world's electronics, and the findings are damning.

The coltan comes from the Rubaya mines in Masisi, North Kivu province, which produce 15% of the world's tantalum, a key ingredient in the capacitors found in smartphones, laptops and cars. Since late 2023, the M23 rebel group backed by Rwanda's military has seized control of these mines, monopolising coltan exports and turning them into a major revenue source for its brutal war in the Democratic Republic of Congo.

The Scale of the Smuggling

Rwanda's own official figures tell the story. Coltan exports have increased more than 2.5 times between 2021 and 2025, a surge that directly mirrors the smuggling boom. Other countries' import records suggest the real volumes are even higher, with over 2,900 tonnes recorded in 2024 alone.

The UN has described the contamination as the "largest contamination of mineral supply chains" in the Great Lakes Region in a decade. At least 1,400 tonnes of coltan have been smuggled from DRC to Rwanda within a year of M23's takeover of the Rubaya mines.

Coltan has become Rwanda's second-largest export earner after gold since 2023. Yet experts, geological studies and the UN have repeatedly pointed out that Rwanda's mineral export figures do not correspond with its actual production capacity. The Rwanda Development Board has declared annual 3T mineral production of 8,000 to 9,000 tonnes, a claim contradicted by independent data.

Rwandan Officials Are Complicit

This is not a case of smuggling happening behind the government's back. Global Witness found direct evidence that Rwandan officials facilitate the trade.

Since M23's takeover of Goma, much of the coltan now crosses the border in plain sight of Rwandan border officials. Global Witness has observed officials recording coltan coming from the DRC. A coltan smuggler told Global Witness the Rwandan authorities are fully aware of what is happening.

Inside Rwanda, once the coltan arrives in Kigali, nobody bothers about where the minerals came from, according to traders interviewed by Global Witness. The Rwanda Mines, Petroleum and Gas Board did not reply to questions on the matter. Global Witness found no evidence that Rwandan officials had confiscated any smuggled coltan in the last two years.

Rwanda has also repeatedly refused to apply the analytical fingerprint, a German-developed tool that can verify the origin of minerals based on their geochemical composition. Rwanda has blocked an inquiry into mineral smuggling by the International Conference on the Great Lakes Region.

M23's War Economy

M23 has designated Erasto Bahati as Governor of North Kivu in its parallel administration. Bahati is the key figure behind the group's illegal mining and mineral smuggling since the takeover of the Rubaya mines.

Traders pay "taxes" on coltan: US$4 per kilo to M23 and US$3 per kilo to the Rwandan government. By collecting these taxes, M23 has generated US$800,000 every month since May 2024, according to UN estimates.

Workers at the mines face brutal conditions. Those who defy M23 orders are beaten and fined. There have been at least four deadly landslides since the takeover. Evidence shared with Global Witness shows children working at the sites.

The Seven Companies Behind 85% of Exports

Global Witness identified seven Rwandan companies that exported 85% of the coltan between January 2023 and September 2025: East Group Minerals (1,333 tonnes, 29.7%), Sunrise Metal Company (810 tonnes, 18.1%), African Panther Resources (439 tonnes, 9.8%), Tawotin (411 tonnes, 9.2%), Kanzamin (362 tonnes, 8.1%), Boss Mining Solution (306 tonnes, 6.8%), and Philbert Trading Minerals (155 tonnes, 3.5%).

At least five of these seven companies have directly purchased conflict coltan from DRC's Rubaya mines: African Panther Resources, Sunrise Metal Company, Boss Mining Solution, Kanzamin and Philbert Trading Minerals. Smaller exporters Space Mining and Rani Mining also bought conflict coltan from Rubaya.

The Traceability System Is Broken

ITSCI, the dominant due diligence and traceability system that companies rely on to certify their supply chains as conflict-free, is being used to launder smuggled coltan.

Four traders told Global Witness that smuggled coltan from Rubaya is tagged by ITSCI as having no conflict links. One smuggler explained: "The exporting company in Kigali comes and puts the tags on the coltan from Masisi and thus it becomes Rwandan coltan."

In at least two cases, tags were improperly put on bags by the buyers themselves, not by the government officials responsible for tagging. Another smuggler said he simply calls the Rwandan mining authorities and they bring as many tags as he needs.

The alternative system, Better Mining, is no better. Companies suspended by ITSCI for sourcing conflict minerals have moved to Better Mining, which does not publish the names of its member companies or the risks it identifies.

From Rwanda to Your Electronics

The coltan's journey does not end in Rwanda. It travels to the port of Dar es Salaam in Tanzania, and from there to smelters primarily in China, Kazakhstan and Thailand. Seven companies purchased almost 80% of the coltan: Minterra (1,252 tonnes), Halcyon (581 tonnes), Traxys (567 tonnes), East Rise Corporation (401 tonnes), Novacore (296 tonnes), Ningxia Orient Tantalum Industry Co. (234 tonnes) and Jiujiang Jinxin Non Ferrous Metals (211 tonnes).

China is the top destination, with Rwanda becoming China's second-largest coltan supplier after Nigeria in 2023. Six Chinese smelters and two others in Kazakhstan and Thailand processed the bulk of the exported coltan. Among them, the state-owned Ningxia Orient Tantalum Industry Co. (OTIC) is a subsidiary of CNMC, itself a subsidiary of a Chinese state-owned conglomerate.

At least four of the eight smelters have likely processed conflict coltan from Rubaya. Yet all eight were assessed as compliant by the Responsible Minerals Assurance Process (RMAP), the leading audit for smelters. The audits failed to identify conflict links in any of them.

The Brands on the Other End

The tantalum processed from this coltan ends up in capacitors manufactured by five major companies: Kemet, Kyocera AVX, Vishay, Panasonic and Hongda Electronics. From there, it enters products sold by some of the world's best-known brands.

Amazon, Microsoft, Vodafone, Toyota, Sony, Nvidia, Honda, LG Display and Ericsson all report having products from smelters that, according to Global Witness's research, have sourced conflict coltan from Rubaya. Apple lists one of the smelters, Ulba in Kazakhstan, as a processor in its supply chain. Apple, once seen as a leader on responsible sourcing, stopped listing its suppliers in its report to the US Securities and Exchange Commission in 2024.

What Needs to Happen

Global Witness recommends that companies stop buying coltan from Rwanda until M23 has withdrawn from the Rubaya mines. The international community should suspend military equipment exports to Rwanda, make development assistance conditional on Rwanda stopping its support for M23, and sanction commanders of M23 and senior Rwandan officials responsible for abuses.

The EU should enforce its conflict minerals regulation. The US should strengthen enforcement of section 1502 of the Dodd-Frank Act and avoid tying resource extraction agreements to security guarantees.

Every time you pick up your phone, open your laptop, or get in your car, there is a chance the tantalum inside it was mined by workers under the threat of violence in eastern Congo, smuggled through a system designed to hide its origins, and certified as clean by auditors who failed to look. The system built to prevent conflict minerals from reaching global markets has collapsed. The question is no longer whether it is happening, but who will stop it.

Based on reporting by GLOBAL WITNESS