Children were brought to Belgium and adopted by families who had been told they were orphans.
Hundreds of miles north of DR Congo’s capital, Kinshasa, is the village of Gemena.
One photo shows them with a young man from a youth organisation, their chaperone to the so-called holiday camp.
Other people have been indicted both in Belgium and DR Congo, the lawyer has told the BBC.
“You have to see all of these people collectively as a truly criminal organisation, that is well organised in DR Congo and in Belgium.”