Actor Heath Ledger, 28, who skyrocketed to fame in his role as a gay cowboy in the Oscar-winning movie "Brokeback Mountain," was found dead in a New York residence on Tuesday, police said. Police sources told US media that prescription pills were found near the body of the Australian native, and said signs pointed to either an accidental overdose or suicide. An autopsy was scheduled for Wednesday. A police spokesman said the actor was "found dead at 3:26 pm (2036 GMT) this afternoon" in an apartment in the posh district of Soho. The cause of the death is still unknown. The entertainment website TMZ said Heath was discovered "face down on the floor" adding that "law enforcement sources ... believe it was not a crime." The New York Times said Ledger was discovered by the housekeeper and a masseuse who arrived in the afternoon for an appointment. They knocked on the door, but "when no one answered, the housekeeper and the masseuse opened the bedroom and found Mr Ledger naked and unconscious on a bed, with pills scattered around his body," the Times said. "They moved his body to the floor and attempted to revive him, but he did not respond. They immediately called the authorities," the Times said. The newspaper initially said police officials believed that the apartment was inhabited by actor Mary-Kate Olsen, 21, and that Ledger was renting it from her. However, a representative for the actress later denied this, telling the paper: "She does not own the apartment. She has never owned the apartment." Australian star Nicole Kidman expressed shock at Ledger's death. "What a tragedy. My heart goes out to his family," Kidman said in a statement to celebrity news show "Extra." Ledger, who was nominated for a best actor Oscar for his portrayal of a gay cowboy in the 2005 film "Brokeback Mountain," had separated from his former fiancee Michelle Williams in September. The pair, who met on the set of the Ang Lee-directed drama, have a two-year-old daughter, Matilda Rose. Ledger had been working this month on his latest movie, "The Imaginarium of Doctor Parnassus," directed by Terry Gilliam, which was due out next year. He also portrays The Joker in the upcoming Batman movie "Dark Knight." Lee had hailed Ledger's performance in "Brokeback Mountain" as a "miracle" of acting, reminiscent of a young Marlon Brando. Ledger lost the Oscar for best actor in 2006 to Phillip Seymour Hoffman for his portrayal of author Truman Capote in "Capote," but "Brokeback Mountain" won three Academy Awards, including for best director. The flaxen-haired heart throb first came to prominence by acting as a homosexual athlete in little-known Australian soap opera "Sweat" in 1996. The creator and writer of the series, John Rapsey, said it was clear even then that Ledger, then a 16-year-old sports champion and high school dropout, possessed an unusual talent. "He himself had absolutely no problem playing the role. He handled all of that with great aplomb," Rapsey told AFP. "What was noticeable about him was he was concentrated, very quiet, and you could see that he was really observant of other people." Ledger, who has never attended acting school and who left his home state of Western Australia for Sydney as a teenager, credited his instincts with his success. "The one thing that's got me to where I'm sitting is my instincts, you know, and I'm impatient. I didn't want to wait for years to work. I wanted to just get out there and do it," he said in an Australian television interview in 2001. At 19, Ledger left Sydney for Hollywood, where his standout talent was spotted by Mel Gibson when auditioning 500 actors for the role of his son in "The Patriot" -- a big-time break that led to his leading role in "A Knight's Tale." Gibson has described Ledger as possessing "the unknown factor" that "sort of lights up the screen". Ledger continued his steady impact on Hollywood, with a small role in "Monster's Ball" (2001), followed by the lead in the lightweight "The Four Feathers" (2002), Australian drama "Ned Kelly" (2003) and "The Brothers Grimm" (2005). Tribute Video