Colonel Setako, whose trial has not yet started, is accused of genocide, crimes against humanity and war crimes.
In a decision Monday, the judges ordered the prosecutor to give precise details concerning the places, dates, authors and victims of certain crimes alleged in the indictment.
The prosecutor has a five-day deadline for the clarifications, which had been requested by Setako's lead counsel, American Professor Lennox Hinds.
Setako was arrested in February 2004 in a center for asylum seekers in The Netherlands.
The former officer, who has pleaded not guilty, is accused of having taken part in the massacres of the civilian Tutsi population in Ruhengeri, in the north, and Kigali, the capital.
Setako was also shareholder of the Radio-Television Libre des Mille Collines (RTLM), which encouraged the massacres of Tutsis in 1994 their broadcasts.
© Hirondelle News Agency