The Quebec Court of Appeal said Wednesday it has upheld the conviction against Rwandan war criminal Desire Munyaneza.
Munyaneza's trial heard he raped women, participated in the slaughter of hundreds of people inside a church and used sticks to beat children tied up in sacks.
He was found guilty in May 2009 of several charges relating to rape and civilian massacres in Rwanda and later sentenced to the maximum life in prison.
His lawyers filed an appeal almost immediately thereafter.
In a decision released Wednesday, the province's highest court dismissed the multipronged appeal of the landmark verdict.
"In the court's opinion, these arguments have no merit," the appeals court ruled.
Munyaneza appealed on several grounds, alleging poorly defined charges, irregularities and misrepresentations by the trial judge and a lack of credibility in Crown witnesses.
But the three justices who listened to the arguments over three days in April 2013 picked apart the arguments of Munyaneza's lawyers and said it was clear he played a central role in the crimes.
"Almost all of the Crown witnesses, who for the most part were in no way connected with each other, stated that the appellant acted as a leader during the events that took place in the Butare prefecture between April and July of 1994," they wrote. "That is why the (trial) judge found that he was 'at the forefront of the genocidal movement'.
"Instead of refraining and refusing to take part in the genocide, he chose to participate actively as Interahamwe (Hutu militia) leader and as a member of the local elite."
The offences took place in and around Butare, where Munyaneza, the son of a wealthy local businessman, was an influential figure. They were part of the tragic events surrounding the genocide of 800,000 Rwandans — mostly minority Tutsis and moderate Hutus, between April and July 1994.
Munyaneza arrived in Toronto in 1997 seeking refugee status but his claim was rejected. He was arrested by the RCMP at his Toronto-area home in 2005 and eventually convicted on seven charges related to genocide, war crimes and crimes against humanity.
In October 2009, Munyaneza was sentenced to life in prison without parole for 25 years, despite pleading for leniency on the issue of parole eligibility.
With time served, Munyaneza was expected to be eligible for parole at the earliest in 2030.
The appeals court ruling also confirms the validity of the country's war-crimes legislation, which was under the microscope during the expensive, secretive and lengthy trial.
Quebec Superior Court Justice Andre Denis oversaw the two-year case and heard from 66 witnesses in court proceedings that were held in Canada, Europe and Africa.
Many of those witnesses were heard behind closed doors and had their identities hidden to shield them from reprisals.
The Munyaneza case has been followed intently by international legal observers as it was the first test of prosecuting someone in a Canadian court for crimes committed abroad.
Munyaneza was convicted under Canada's Crimes Against Humanity and War Crimes Act, enacted in 2000.