Theoneste Bagosora, the Rwandan military leader dubbed the "Colonel of the Apocalypse", has died at the age of 80 in Mali where he was serving a sentence for his role in the 1994 Genocide against the Tutsi.
Bagosora's death was announced by his son in a Facebook post on Saturday that read "R.I.P. Papa". It was confirmed on Sunday.
"Theoneste Bagosora died in a hospital in Mali yesterday (Saturday) late morning," said Abubacarr Tambadou, registrar for the Mechanism for International Criminal Tribunals, which oversees prosecution of those responsible for the genocide.
Bagosora was jailed for life in 2008 for genocide, crimes against humanity and war crimes. His sentence was reduced to 35 years on appeal in 2011.
In April 1994, Colonel Bagosora was the most senior official under the minister of defence.
Once a close ally of then president Juvenal Habyarimana -- they both came from the same northwestern province of Gisenyi -- he later reportedly held a grudge after being passed over for promotion to general.
French military intelligence concluded that Bagosora was one of the prime sponsors behind the April 6 assassination of both president Habyarimana and his Burundian counterpart Cyprien Ntaryamira, as well as the Rwandan army chief of staff.
Their Falcon plane was shot down when preparing to land in the Rwandan capital Kigali, an event many blamed on rebels and which triggered the massacres.
A few days later, the Foreign Minister Boniface Ngurinzira was killed by soldiers. Bagosora and Ngurinzira had clashed constantly during 1993 peace talks in Tanzania.
Bagosora accused Ngurinzira of making too many concessions to the rebels and, on his return to Rwanda, reportedly said he was heading home "to prepare the Apocalypse" -- something he denied in court hearings.
Bagosora denied any direct role in the Genocide against the Tutsi, though he was seen as part of an extremist faction in the country.
With the defence minister also out of the country on a mission, Bagosora was the most senior military official from April 6-9, the first days of the Genocide against the Tutsi.
The appeal court in 2011 found that while there was no evidence he ordered the massacres, Bagosora knew they were planned and did nothing to stop them even though he was in a position to do so.
Before his death, Bagosora was serving his sentence in Koulikoro prison in Mali, but had been transferred to a clinic in the capital Bamako, an official in the Malian prison administration told AFP.
An official at the institution where he was admitted said he died of "heart failure", without giving further details.
Bagosora had in April been refused an application for early release because of the "extremely high gravity (of his) crimes".