Entitled "Faced With A Gun, What Can You Do?" the report names a number of high-profile companies it says are involved in buying minerals from questionable sources within the DRC who use the money to fund violent armed conflict in the region.
The report states:
The militarization of mining in eastern Democratic Republic of Congo (DRC) is prolonging the armed conflict which has been tearing the country apart for more than 12 years.
In their broader struggle to seize economic, political and military power, all the main warring parties have carried out the most horrific human rights abuses, including widespread killings of unarmed civilians, rape, torture and looting, recruitment of child soldiers to fight in their ranks, and forced displacement of hundreds of thousands of people. The lure of eastern Congo's mineral riches is one of the factors spurring them on.
The UN currently estimates that 1.6 million people are displaced in the eastern provinces.
Global Witness names AMC, THIARSCO, Trademet and Afrimex among the companies they say are linked to the DRC violence.
In 2007, after Global Witness made similar claims again Afrimex, a UK government group found the company guilty of breaching the OECD guidelines for trading in conflict regions. Global Witness claims that Afrimex still needs to be more thorough in tracing its supplies.
Patrick Alley, Director of Global Witness, said, "It is not good enough for companies to say they buy only from licensed exporters, when they know full well that their middlemen buy from armed groups. The failure of governments to hold companies to account, of Burundi and Rwanda to restrict the trade across their borders, and of donors and diplomats to address explicitly the role of the mineral trade, have all contributed to the continuation of a conflict that has killed millions and displaced many more."
The report calls on the British government to step up and challenge the breaches to the OECD's guidelines on trading with groups in conflict countries.
Global Witness also states that AMC-subsidiary company THAISARCO sources supplies through a firm which sells minerals from mines controlled by the FDLR Hutu extremist group which was involved in the Rwandan genocide in 1994.
The International Crisis Group recently stated that the FDLR troops continue to be extremely violent towards civilians.
The Mirror reports that some of AMC's main shareholders have appeared on the Sunday Times Rich List.
In a statement released today, AMC said that both it and its subsidiary company THAISARCO are in compliance with the UN requirements regarding DRC mineral sourcing, and say the Global Witness report contains a number of inaccuracies in relation to their operations.
"AMC and THAISARCO have the objective, in common with most of the participants and stakeholders involved in the trade of Congolese Cassiterite, of improving the visibility and traceability of the supply chain in order to ensure that warring groups do not benefit from the trade," the statement said.
"If the UN were to decide that dissociation from the trade is the most appropriate way forward, then THAISARCO would comply absolutely with such a requirement. "
The AMC group also quoted a World Bank estimate that up to 10 million people in the DRC are dependent on the mineral trade.
Refuting this dependency argument, Lizzie Parsons from Global Witness, writes in the HuffPost:
"Some people argue that the trade shouldn't be meddled with because of the multitude of Congolese miners and their families who depend on in. Such arguments ignore the current atrocities. Hundreds of thousands of people in the region have been forced to flee from their homes - some many times - because men with guns have given them no choice. Others have been massacred, raped or tortured. The status quo should not be an option here."