A former Baptist church pastor from Rwanda is facing a life sentence for his alleged role in the massacre of Tutsis in the 1994 genocide.
Francois Bazaramba will face trial in Finland, where he now lives.
He denies having any role in the genocide, and is pleading not guilty to all charges against him.
The case is being heard in Finland because the country signed an international agreement to investigate and try genocide cases if the suspects live in Finland.
It will be heard by a panel of four judges who will also travel to hear evidence in Rwanda.
Alan Fisher reports from the Finnish town of Porvoo.