DR Congo conflict: Mobile phones, coltan and the fighting

The US’ Dodd-Frank Act passed in 2010, and a similar piece of EU legislation, is aimed at ensuring that companies purchasing tin, tantalum, tungsten and gold – so-called “conflict minerals” – are not inadvertently funding violence.

But Itsci has come under some criticism.

Ken Matthysen, a security and resource management expert with independent research group Ipis, highlights that the dispersed nature of a lot of small-scale mines make it difficult for the local authorities to monitor exactly what is going on everywhere.

Itsci tags should be put on bags at the mine itself, to prove the origin of the minerals inside, but often they get transported to a collection point where it becomes harder to trace where the ore actually came from, Mr Matthysen said.

He added that there is also a possible issue with corruption.

“There is even an accusation of the state agents selling tags to traders, because they don’t make a good living. So the traders then go around eastern DR Congo and they tag the bags themselves.”

Itsci did not respond to a BBC request for comment, but has in the past defended its record saying that the scheme has been subjected to a rigorous independent audit. It has also been praised for bringing “prosperity for hundreds of thousands of small-scale miners”.

In the case of Rubaya, Itsci suspended its operations there soon after the M23 entered the town.

Nevertheless, the group has managed to continue exporting coltan.

The UN experts map a circuitous route showing how it is transported to close to the Rwandan border. It is then transferred to “heavy-duty trucks” that needed the road to be widened in order to accommodate them.

Rwanda has its own coltan mines but the experts say that the uncertified coltan is mixed with Rwandan production leading to a “significant contamination of supply chains”.

The M23 was already involved in the coltan business before the capture of Rubaya – setting up roadblocks and charging fees to cross them, according to Mr Matthysen.

“A lot of the trade of these minerals went through M23-controlled area towards Rwanda. So even then, Rwanda was profiting from the instability in eastern DR Congo and we saw the export volumes to Rwanda were already increasing,” he told the BBC.