Belgium has started a criminal probe into allegations that Apple has knowingly sourced “blood minerals” from the Democratic Republic of Congo, in what lawyers for the central African country have called a “massive laundering and greenwashing operation”.

In December, the DRC filed criminal complaints in Belgium and France against subsidiaries of the US tech group, alleging they used minerals supplied by armed groups committing atrocities in eastern Congo.

Lawyers acting for DRC said prosecutors in Belgium had last week appointed an investigative judge — who oversees the investigation and is in charge of issuing arrest warrants, wiretaps and raids — to probe the case. They were still awaiting a decision from France, where the process was slower.