Leading Rwandan opposition politician Seif Bamporiki has been shot dead in South Africa, where he lived in exile.
Mr Bamporiki was pulled from his vehicle in a township in Cape Town before being killed, police said.
Preliminary investigations showed he had been killed in a robbery, police said. But Mr Bamporiki’s party, the Rwanda National Congress (RNC), said the motive was still unclear.
Rwanda has previously been accused of targeting dissidents in South Africa.
It has consistently denied the allegation.
The RNC was formed in exile by opposition politicians who accuse President Paul Kagame’s government of being authoritarian, and of being intolerant of dissent.
Mr Bamporiki ran a bed shop in Cape Town. He was making a delivery in Nyanga township on Sunday when he was shot after being confronted by two men, police said.
“The deceased was pulled from his vehicle and shot while the 50-year-old man who accompanied him managed to escape unharmed.
“The suspects who are yet to be arrested fled with the deceased’s vehicle, and we have reason to believe that the motive for the murder was robbery,” police added in a statement to the BBC.
RNC spokesman Etienne Mutabazi gave a different account, saying Mr Bamporiki was killed after a gunman fired a single shot through the window of the car.
There was speculation on social media that Mr Bamporiki had been killed in a political hit, but Mr Mutabazi said he did not know whether this was the case, reports the BBC’s Nomsa Maseko from South Africa’s main city, Johannesburg.
Nyanga is known to be one of the most dangerous townships in South Africa, with a high rate of crime, she adds.
Rwanda’s former intelligence chief and RNC founding member Patrick Karegeya was murdered in a hotel room in Johannesburg in 2014.
Another RNC founding member, former army chief Gen Faustin Nyamwasa was shot and wounded in Johannesburg in 2010.
The attacks caused a huge diplomatic row between South Africa and Rwanda in 2014.
South Africa expelled three Rwandan diplomats after accusing them of links to the murder and attempted murder of Rwandan dissidents living in the country.
Rwanda’s government dismissed the allegation.