Scores of anti-Kabila protesters were killed in recent clashes with security forces.
Kabila has been accused of trying to stay in power by delaying elections in Congo.
Elections scheduled for November look likely to be delayed until at least July 2017.
The killings took place in Beni, a conflict hotspot in eastern Congo.
The Congolese government has expelled several foreign researchers already in 2016.
The judge claims the government wants to cripple Katumbi's political ambitions.
The Congolese musician was deported from Kenya following the incident.
The International Criminal Court gives Jean-Pierre Bemba 18 years for 2002-03 actions in Central African Republic.
The untold story of the wartime dash to obtain Congo's uranium, crucial to the atomic bomb.
The 83-year-old politician has opposed successive governments and says he'll run again in 2016.
Darryl Lewis worked for opposition presidential candidate Moise Katumbi, a challenger to President Joseph Kabila.
Elections are scheduled for November in the conflict-torn, mineral-rich African country.
Congo could go the way of Burundi in President Kabila tries to stay in power, according to one analyst.
The football club owner and presidential candidate has been accused of recruiting mercenaries.
Katumbi, the owner of a football club, announced he would run for the Congolese presidency last week.
The Congolese musician died after collapsing on stage on Sunday.
The violence reportedly targeted Hutus in retribution for the killing of members of the Nande ethnic group.
Ladislas Ntaganzwa is accused of killing and raping thousands of people during the 1994 genocide.
The group has come to prominence for its violence even by the standards of one of Africa's most troubled countries
Deaths included seven civilians who were hacked to death in a hospital