The International Criminal Court is to pass judgment on alleged Congo warlord Germain Katanga in a key test of the prosecutors' ability to bring solid cases and win convictions at the Hague-based tribunal.
The court, launched in 2002 to try crimes against humanity, has handed down only two verdicts so far - a conviction and an acquittal - while at least five cases have collapsed for lack of sufficient evidence before or during trial proceedings.
Apart from accusations of slow justice, the court has also suffered from criticism that it has so far only brought charges against Africans while atrocities in conflicts in the politically-charged Middle East go unpunished, according to a Reuters news agency report.
Friday's case stems from a bloody conflict that killed 200 people in the resource-rich Ituri region of northeast Congo in the early 2000s.
Katanga was charged with 10 counts of war crimes and crimes against humanity related to an attack on a village called Bogoro by an armed group he allegedly commanded, the Patriotic Resistance Force.
Prosecutors allege that the man, once known as "Simba" (Lion), and his forces of the Ngiti and Lendu tribes attacked villagers of the Hema ethnic group with machine guns, rocket-propelled grenades and machetes, murdering about 200 people.
"The attack was intended to 'wipe out' or 'raze' Bogoro village...," the prosecution said, according to an AFP news agency report.
Child soldiers were used while women and girls were abducted afterwards and used as sex slaves, forced to cook and obey orders from Patriotic Resistance Force soldiers.
Katanga denies ever being present at the time of the attack and maintains that he had no direct command or control over the soldiers. He could face a life sentence if convicted.
He was charged alongside Mathieu Ngudjolo Chui, another militia leader who was acquitted for lack of evidence last year.
Judges separated Katanga's case before the verdict and gave prosecutors another year to gather more evidence that he had contributed to the crimes, not that he was central to them as originally charged.
"If they don't clear this lower bar, it will put a question mark over the organisation of the trial," said Carsten Stahn, a law professor at Leiden University.
"Even if they do end up with a conviction, it will remain a fragile basis for conviction."