OSLO, Norway (AP) — Abdul Ruzibiza, a former captain of a Tutsi rebel group and key witness in a French judge's investigation into a 1994 attack that triggered the Rwandan genocide, has died, Norwegian police said Friday. He was 40.

Ruzibiza died in a Norwegian hospital Wednesday after a long illness, said Reidun Brekke, who was Ruzibiza's supervisor at staffing company Adecco Norway.

A former captain of the Rwandan Patriotic Front, Ruzibiza released a book in 2005, saying the group was behind the 1994 attack that shot down then-President Juvenal Habyarimana's plane.

The incident set off attacks in the central African nation by extremists members of the Hutu majority who killed Tutsis and moderate Hutus. About 500,000 people, mostly ethnic Tutsis, were killed in 100 days.

Ruzibiza's testimony has been instrumental in an investigation led by a French judge who in 2006 concluded that current Rwandan President Paul Kagame ordered the attack.

Rwanda cut off diplomatic ties with France as a result in 2006 and restored them in November 2009. The Rwandan government's own investigation, released in January, suggested that the plane was shot down by Habyarimana's allies as an excuse for starting the genocide.

Information on survivors and funeral arrangements was not immediately available.