Prominent Cameroonian gay rights activist and journalist Eric Lembembe has been killed in the capital, Yaounde, a rights group says.
Mr Lembembe's neck and feet appeared to have been broken and his face, hands, and feet burned with an iron, Human Rights Watch (HRW) said.
The cause of the killing is not known, but Mr Lembembe is the latest activist to be targeted in Cameroon, it added.
Homosexual acts are illegal in socially conservative Cameroon.
"The police should not rest until the perpetrators of this horrific crime are brought to justice. President Biya should break his silence on the wave of homophobic violence in Cameroon and publicly condemn this brutal attack," said HRW researcher Neela Ghoshal in a statement.
Mr Lembembe, the executive director of the Cameroonian Foundation for Aids, was a courageous activist who campaigned for equal rights, despite severe discrimination and violence, HRW said.
His friends discovered his body at his home in Yaounde on Monday, after being unable to reach him by phone for two days, it said.