André Kagwa Rwisereka was vice chairman of the Democratic Green Party until he was assassinated outside the city of Butare last week.
Friends and relatives gathered today in Butare's Roman Catholic cathedral to pay their respects to the senior politician.
Frank Habineza, the chairman of the Democratic Green Party, said he had learned a lot from Rwisereka. Speaking from Kigali, he told RFI's Michel Arseneault his mentor was "a very brave person always ready to risk himself for the sake of others."
Arseneault asked Habineza if he was confident the police would do their best to find the murderers.