A US law requiring companies to track the source of minerals used in manufacturing their products is worsening poverty and fuelling violence in the Democratic Republic of Congo, researchers and US Congress members have said.

As a result, many American companies have stopped buying minerals from the DRC, says a memorandum from a US Congress panel.

The “de facto embargo against the DRC” is further impoverishing the Congolese, whom the law was intended to help, the memo says. This in turn is perpetuating violence in the mining areas.

Republican members of the Congress are opposed to the law, which is part of a set of reforms enacted after the 2008 Wall Street financial crisis.

The Obama administration supports the effort to curb extraction of minerals that help finance war in the eastern DRC. The “conflict minerals” law was enacted in 2010 after intensive lobbying by human rights groups such as Amnesty International and Global Witness.

At last week’s Republican-sponsored hearing on the law, opponents said it could negatively affect 12 million Congolese, who depend on mineral trade.

The committee further noted that the cost of meeting the requirements for US firms would be about $8 billion.

The law “ignores the will and agency of the Congolese people and imposes an outside solution to a problem that is best understood by the Congolese,” Mvemba Phezo Dizolele, a visiting fellow at a California think tank, told the committee.

“We have to resist the urge to impose Western activists’ vision of the world on the Congolese,” Mr Dizolele added.

A Congo native, Mr Dizolele is a US citizen affiliated to the Hoover Institution on War, Revolution and Peace.

“The emergence of the M23 militia last year, which escalated tensions in the Great Lakes, is proof that this law has little bearing on war entrepreneurs.”

But Sophia Pickles, a researcher at the London-based Global Witness, cautioned that it was too early to measure the impact of due diligence as the law had been in effect for only five months.

Global Witness disputes the claims that the law has resulted in an embargo on purchases of tantalum, tin, tungsten and gold from DRC.

Ms Pickles also rejected the contention that the advocacy for sanctions on “conflict minerals” did not reflect the views of the Congolese.

She said her organisation’s work on mineral trade in central Africa was “informed by regular, in-depth field investigations in eastern DRC, Rwanda and Burundi.”

The group’s representatives visit mines in the region and speak with local traders as well as smugglers, mining sector authorities and ministers of the DRC, Rwanda and Burundi.

Ms Pickles said DRC officials supported the conflict minerals law, adding that the Congolese Minister of Mines said the law offered a “major opportunity” to break the link between minerals and violence.