Actor Heath Ledger, the gifted leading man acclaimed for his role as a gay cowboy in the film “Brokeback Mountain,” was found dead in his Manhattan apartment on Tuesday, possibly of a drug overdose, police said.

Police spokesman Paul Browne has confirmed Perth-born Ledger, 28, was found dead by a housekeeper at his apartment in the trendy SoHo neighbourhood.

“We are investigating the possibility of an overdose,” Mr Browne said.

According to Mr Browne, the housekeeper found Ledger at 3:26pm (7:26am AEDT) and tried to wake him for his appointment to have a massage.

Pills were strewn around the bed, and there was a bottle next by the actor’s body, police sources said. The maid and therapist called 911 at about 3:26 p.m. Emergency workers were unable to revive the star, and he was pronounced dead at 3:35 p.m.

Bottles of the generic forms of Xanax and Valium, both anti-anxiety drugs prescribed in his name, were found in the house, according to law-enforcement sources. The sleeping drug Ambien was also found near his body, sources said. The maid said she last heard the star snoring around noon.

Screen star Mel Gibson, who starred alongside Ledger in the film “The Patriot,” said his thoughts and prayers were with the younger actor’s family.

“I had such great hope for him,” Gibson said in a statement released by his publicist. “He was just taking off and to lose his life at such a young age is a tragic loss.”