Romeo Dallaire, 61, was to appear as a "context witness" against a Rwandan failed refugee claimant charged with war crimes, genocide and crimes against humanity for his alleged role in the 1994 Rwandan genocide, the Montreal Gazette reported.

Desire Munyaneza, 40, is the first person charged under Canada's war crimes and crimes against humanity law, which was passed in 2000. His trial began in March, and he is in protective custody after surviving a prison beating last spring in Montreal.

Dallaire never had contact with Munyaneza in Rwanda but is considered a good witness by prosecutors because of his exposure to the tribal fighting between Tutsi and Hutus in which an estimated 800,000 people died, the report said.

After leaving the conflict, Dallaire attempted suicide three times and was diagnosed with post traumatic stress disorder. He retired from the military and is now an appointed federal senator.