French prosecutors have settled a case in the Democratic Republic of Congo accusing an Apple subsidiary of using conflict minerals in its supply chain, according to a document seen by Reuters on Thursday. Congo has filed criminal charges against Apple subsidiaries in France and Belgium, its lawyers said in December. Apple said at the time that it strongly disputed the allegations and had told its suppliers not to use related minerals from Congo or Rwanda.

In the document, dated February 18 and seen by Reuters, the Paris prosecutor's office said there was "insufficient evidence" on charges of money laundering and deceptive business practices and had closed the case - meaning the office would no longer proceed with the complaint.

The office invited Congo to contact other offices "with jurisdiction over war crimes."

The prosecutor's office and Apple did not immediately respond to emailed requests for comment Thursday.

Congo is a major producer of tin, tantalum and tungsten - the so-called 3T minerals used in computers and mobile phones. Some artisanal mining sites are run by armed groups that are involved in massacres of civilians, mass rapes, looting and other crimes, according to U.N. experts and human rights groups.

Since the 1990s, eastern Congo's mining heartland has been ravaged by fighting between armed groups, some backed by neighboring Rwanda, and the Congolese military.

The complaint to France and Belgium was prepared on behalf of the Congolese Minister of Justice. A Congolese lawyer said in January that Belgium responded by appointing an investigating judge.