Col Theoneste Bagosora, the man considered the key architect of the Genocide against the Tutsi, has died in a Malian prison.

The development was confirmed by family sources on Saturday. Bagosora was serving a 35-year sentence handed to him by the then International Criminal Tribunal for Rwanda (ICTR).

Though they did not divulge more details, family sources announced that the 80-year-old succumbed to disease and died in a hospital in Mali, where he had been imprisoned since 2012.

Bagosora was arrested in March 1996 and transferred to the ICTR in Arusha, Tanzania where he was tried for his role in the 1994 Genocide against the Tutsi.

He was the highest authority in the Ministry of Defence and exercised control over the army of the genocidal regime that worked with Interahamwe to slaughter Tutsis.

Among other crimes, he bears superior responsibility for the systematic killing of prominent personalities and opposition political figures who were a threat to the genocidal plan on the morning of April 7, 1994.

These include the then Prime Minister Agathe Uwilingiyimana, Joseph Kavaruganda who was the President of the Constitutional Court, Frédéric Nzamurambaho who chaired the Parti Social Démocrate and was Minister of Agriculture, as well as Landouard Ndasingwa who was the local government minister at the time among many others.

Bagosora was on December 18, 2008, found guilty of genocide, murder, extermination and persecution as crimes against humanity, violence to life and outrages upon personal dignity, as well as rape.

He was, therefore, sentenced to life imprisonment.

However, on December 14, 2011, the Appeals Chamber, then presided over by controversial Judge Theodore Meron, reduced his sentence to 35 years in prison.

He had recently requested for early release but this was struck down by the President of the Mechanism for International Criminal Tribunals - which took over from ICTR - citing lack of remorse as one of the reasons he had to serve the full length of his sentence.