The judges withdrew themselves to deliberate at the end of two days of closing arguments, during which the prosecutor requested life in prison for the accused whereas the defence called for an acquittal.
Zigiranyirazo, 70, is represented by two Canadian lawyers: John Philpot and Peter Zaduk.
The defence considered that the prosecutor had not provided evidence that would make it possible for the Chamber to convict Zigiranyirazo.
Zigiranyirazo is accused of having conspired in the planning of the Tutsi genocide and to have personally taken part in some attacks.
Speaking specifically about a massacre perpetrated in Kesho, in northern Rwanda, on 8 April 1994, the defence argued that Zigiranyirazo was in Kigali mourning the death of his brother-in-law Habyarimana, killed in an attack on his plane two days earlier.
The Zigiranyirazo trial began on 3 October 2001. As at the opening of his trial, the defendant, who was authorized to address the Chamber, considered it regrettable that the ICTR had still not investigated the attack against the plane of Habyarimana.
"Why this total disinterest of the international community vis-a-vis an attack which cost the life of two democratically elected presidents, and in the course of the performance of their duties, whereas it hastened to order investigations into the attack against the former Lebanese Prime Minister Rafik Hariri. Why two different standards? ", questioned Zigiranyirazo.
Habyarimana was killed together with the Burundian President Cyprien Ntaryamira, who were both returning in a same plane from a regional peace meeting in Tanzania.
Zigiranyirazo said that the prosecutor accuses him of having taken part in the extermination of Tutsis "whereas we always maintained correct relations.
"I swear before you and I take God as a witness, I never took life of anybody, nor taken part in any conspiracy to do so", claimed the defendant.
© Hirondelle News Agency