RCMP have arrested a Rwandan immigrant and charged him with war crimes, capping an exhaustive six-year investigation that involved questioning witnesses far outside Canada's borders.

Police allege Jacques Mungwarere, 37, committed an act of genocide in Kyuye, Rwanda, in connection with that country's horrific slaughter of 800,000 minority Tutsis and moderate Hutus in 1994.

They arrested him at his home in Windsor, Ont., on Friday, and he made a brief court appearance on Saturday.

Mungwarere is only the second person in history to be charged under Canada's Crimes Against Humanity and War Crimes Act.

RCMP investigators say they spoke to witnesses in Rwanda and the United States. But RCMP Sgt. Marc Menard would not divulge any details into the allegations.

"The RCMP's position is that we take this very seriously," he said Saturday.

"We're committed to prosecuting these cases to the full extent of law and we're going to hold those involved in these types of crimes accountable for their actions."

None of the charges against Mungwarere have been proven in a court of law. His trial is set to begin Nov. 12.

Last May, Desire Munyaneza became the first person ever convicted under the War Crimes Act. On Oct. 29, A Quebec judge handed him a life sentence, with no chance of parole for 25 years.

The Act became law in October 2000.

Its purpose is to protect Canada from serving as a hideout for accused war criminals, CTV's chief political correspondent, Craig Oliver, said from Ottawa.

"After the Second World War hundreds of Nazis came to Canada, hid here, were never prosecuted," Oliver said. "I think many people will be heartened that in the case of the greatest genocide since the Holocaust, the 1994 killing of 800,000 people in Rwanda, Canada is not making the same mistake again."

The investigation that led to Mungwarere's arrest took five investigators six years, working in the United States, Canada and Rwanda, he added.

"You have to give some credit to the RCMP for the zealousness with which they're pursuing Rwandan war criminals," Oliver said.

With files from The Canadian Press