Army spokesman Major Guillaume Ndjike told AFP that Habiarimana Mucebo Sofuni had been captured in Rutshuru, in the restive eastern DR Congo's Nord-Kivu province.
Sofuni served as a commander in charge of intelligence for the Democratic Forces for the Liberation of Rwanda (FDLR), created by Rwandan Hutu refugees in the eastern DRC after the genocide of Tutsis by majority Hutus in neighbouring Rwanda in 1994.
A local rights group, the Centre for the Promotion of Peace, Democracy and Human Rights (CEPADHO), said Sofuni had been detained Sunday.
The FDLR, opposed to the current Rwandan government, has not launched any large-scale offensive in Rwanda since 2001. The group is regularly accused of committing atrocities against civilians in the zones under its control in the eastern DRC.
More From This Section
Some of its founders are wanted by international prosecutors, accused of playing an active part in the genocide.
In August the Congolese army arrested Patrick Sabimana -- security chief to Rwandan Hutu leader Sylvestre Mudacumura, who is wanted by the International Criminal Court on war crimes charges including rape, torture and pillage.