The man whose case led to a landmark US Supreme Court ruling that granted privacy rights to gay men and lesbians has died at the age of 68.

John G. Lawrence died in Houston on November 20, according to Sarah Wilson of R.S. Farmer Funeral Home in Silsbee, Texas.

Mr Lawrence died of a heart condition, his partner, Jose Garcia, told the Houston Chronicle.

Mitchell Katine, a Houston lawyer who represented Mr Lawrence in the case Lawrence vs Texas, told the newspaper he learned of his client's death while trying to invite him to an April celebration of the 2003 ruling.

The case began in 1998 when a neighbour with a grudge faked a distress call to police, telling them that a man was "going crazy" in Mr Lawrence's apartment just outside Houston.

Police went to the home, pushed open the door and found Mr Lawrence and Tyrone Garner having sex. Both paid 200 US dollar fines after spending several hours in the county jail for alleged violation of the state sodomy statute, a misdemeanour.

Mr Katine said Mr Lawrence did not view himself as an activist.

"He was angry at how he was treated, both physically and personally," he told the Chronicle. "He was taken to jail in the middle of the night in his underwear."

At the time of the Lawrence ruling, gay rights advocates called it the most important legal advance ever for gay people.