A Ugandan gay rights campaigner who last year sued a local newspaper which named him as being homosexual has been beaten to death, activists say.
Police have confirmed the death of David Kato but say they are investigating the circumstances.
Uganda's Rolling Stone newspaper published the photographs of several people it said were gay next to a headline reading "Hang them".
Homosexual acts are illegal in Uganda, with punishments of 14 years in prison.
An MP recently tried to increase the penalties to include the death sentence in some cases.
Witnesses have told the BBC that a man entered Mr Kato's home near Kampala, and beat him to death before leaving.
His Sexual Minorities Uganda (Smug) group said Mr Kato had been receiving death threats since his name, photograph and address were published by Rolling Stone last year.
Human Rights Watch (HRW) has called for a swift investigation into his death.
"David Kato's death is a tragic loss to the human rights community," said HRW's Maria Burnett.
He had campaigned against the Anti-Homosexuality Bill, which appears to have been quietly dropped after provoking a storm of international criticism when it was mooted in 2009.
Following a complaint by Mr Kato and others, a judge in November ordered Rolling Stone to stop publishing the photographs of people it said were homosexual, saying it contravened their right to privacy.
Several activists said they had been attacked after their photographs were published.