JOHANNESBURG — An exiled former Rwandan intelligence chief and critic of President Paul Kagame has been found murdered in a Johannesburg hotel, South African police said on Thursday.

Patrick Karegeya, who once headed military intelligence in his homeland, fled to South Africa along with former Rwandan army chief Faustin Kayumba Nyamwasa after allegedly plotting a coup against Kagame.

A Rwandan opposition party blamed Kagame's government for Karegeya's death, which it described as an assassination.

Paul Ramakolo, a spokesman for South Africa's Hawks, an elite crime fighting unit, confirmed Karegeya had been killed. "We will check if it was as a result of strangulation or what could be the factor," he said.

The opposition Rwanda National Congress said in a statement dated January 1 that Karegeya's body was found in a hotel where he went for a meeting.

"By killing its opponents, the criminal regime in Kigali seeks to intimidate and silence the Rwandan people into submission," it said.

Spokespeople at the Rwandan embassy in Pretoria were not immediately available to comment on the Rwanda National Congress' accusation.

Rwandan ambassador to South Africa Vincent Karega earlier told local radio SAFM he was not aware of details of the killing but that he knew Karegeya had been in the country for several years and had obtained asylum.

"We encourage the authorities to really look into the matter so that we know exactly what happened," he said.

In 2011, a Rwandan military court sentenced Karegeya, Nyamwasa and two other exiled officers to 20 years in prison for threatening state security after they were tried in absentia.

In 2010, Nyamwasa was shot in the stomach as he drove into the driveway of his upmarket Johannesburg home. He survived what his family said was an assassination attempt ordered by Kagame.

(Reporting by Helen Nyambura-Mwaura; Editing by Ed Stoddard and John Stonestreet)