NEW YORK (AP) - An autopsy on Heath Ledger was inconclusive, and more tests are needed, the medical examiner's office said Wednesday, a day after the 28-year-old actor was found dead with sleeping pills nearby.
It will take about 10 days to complete the investigation, said Ellen Borakove, a spokeswoman for the medical examiner.
Earlier, police said the death was caused by a possible drug overdose and appeared to be accidental.
Fans left flowers and candles outside the apartment building in Manhattan's SoHo where the body of the Oscar-nominated star of "Brokeback Mountain" was found.
Khaled Ali, 41, a stage manager for a Broadway show, dropped off a candle on his way to work. He said he and his fellow cast members were devastated by the news of Ledger's death.
"I felt a connection with him as an actor, as a fellow in the theater community," he said. "With 'Brokeback Mountain' he touched me personally in telling the story of my community. It was very touching."
Ledger was known for grueling, intense roles that became his trademark after he got his start in teen movies like "10 Things I Hate About You."
The Australian-born actor was found dead Tuesday by his housekeeper and masseuse - lying naked and face-down at the foot of his bed, with prescription sleeping pills nearby, police said.
It was a shocking end to a career built on unpredictability. Ledger avoided the safe path in favor of roles that forced him to bury his Australian accent and downplay his leading-man looks: a tormented gay cowboy in "Brokeback Mountain," a drug addict in "Candy," an incarnation of Bob Dylan in "I'm Not There."
In what may be his final finished performance, he took a rare role in a guaranteed summer blockbuster, playing Batman's nemesis, the Joker, in the upcoming "The Dark Knight." But the role was nothing he could phone in; it forced him to rebrand a character last played on the big screen by Jack Nicholson.
"I had such great hope for him," Mel Gibson, who played Ledger's father in "The Patriot," said in a statement. "He was just taking off and to lose his life at such a young age is a tragic loss."
Ledger split last year with Michelle Williams, who played his wife on the set of "Brokeback Mountain." The two had a daughter, the now 2-year-old Matilda, and had lived together in Brooklyn's Boerum Hill neighborhood.
Early Wednesday, Williams and Matilda left Trollhattan, Sweden, where the 27-year-old actress had been shooting scenes for the upcoming film "Mammoth," said Martin Stromberg, a spokesman for film production company Memfis Film.
"She received the news at her hotel late last night," Stromberg said, adding he had not spoken to the actress after she learned of Ledger's death.
The actor's personal strife was accompanied by professional anxiety.
Ledger said in an interview in November that "Dark Knight" and last year's "I'm Not There," took a heavy toll. He said he "stressed out a little too much" during the Dylan film, and had trouble sleeping while portraying the Joker, whom he called a "psychopathic, mass-murdering, schizophrenic clown with zero empathy."
"Last week I probably slept an average of two hours a night," Ledger told The New York Times. "I couldn't stop thinking. My body was exhausted, and my mind was still going." He said he took two Ambien pills, which only worked for an hour.
News of Ledger's death spread quickly, from the crowd of 300 people that gathered Tuesday outside his Manhattan apartment to the Sundance Film Festival in Utah, where those with close ties to the actor included Naomi Watts, who dated him after they met on the set of "Lords of Dogtown," a fictionalized story about the birth of modern skateboarding.
Ledger was born in 1979 in the western Australian city of Perth to a mining engineer and a French teacher, and got his first acting role playing Peter Pan at age 10 at a local theater company. He began acting in independent films as a 16-year-old in Sydney and played a cyclist hoping to land a spot on an Olympic team in a 1996 television show, "Seat."
Speaking in Perth, Ledger's father called the actor's death "tragic, untimely and accidental."
Kim Ledger called his son "down-to-earth, generous, kind-hearted, life-loving, unselfish" and "extremely inspirational to many."
"Heath has touched so many people on so many different levels during his short life," he said. "Please now respect our family's need to grieve and come to terms with our loss privately."
After several independent films, Ledger moved to Los Angeles at age 19 and starred opposite Julia Stiles in "10 Things I Hate About You," a reworking of Shakespeare's "The Taming of the Shrew." Offers for other teen flicks came his way, but Ledger turned them down, preferring to remain idle than sign on for projects he didn't like.
"It wasn't a hard decision for me," Ledger told The Associated Press in 2001. "It was hard for everyone else around me to understand. Agents were like, 'You're crazy,' my parents were like, 'Come on, you have to eat."'
He began to gravitate toward more independent films after roles in "Monster's Ball," "The Patriot" and "A Knight's Tale." His work in 2005's "Brokeback Mountain" earned him an Academy Award nomination for best actor.
In the 2006 film "Candy," Ledger played a poet wrestling with a heroin addiction along with his girlfriend. Neil Armfield, who directed Ledger in the film, said the actor had "handled his career incredibly well," steering himself toward more challenging roles.
"He made a decision about four years ago to stop being led by producers and managers and to forge his own way," Armfield told Australian Broadcasting Corp. radio.
He brought the same intensity to "Dark Knight." Glimpsed in early teaser trailers, Ledger is more depraved and dark than comical. The film's director, Christopher Nolan, said this month that Ledger's Joker would be wildly different from Nicholson's.
"It was a very great challenge for Heath," Nolan said. "He's extremely original, extremely frightening, tremendously edgy. A very young character, a very anarchic presence that taps into a lot of our basic fears and panic."
Ledger was a widely recognized figure in his SoHo neighborhood, where Michelle Vella said she frequently saw him carrying his 2-year-old daughter on his shoulders, or having ice cream with her.
"It's a shock; he's so young," said Taren Dolbashian, who also had seen Ledger with his daughter. "He always seems so happy."
Near the entrance to the building housing his loft, about two dozen bouquets and a dozen candles formed a makeshift memorial.
One note said, "I couldn't find anything bad about you."
Copyright © 2008 The Associated Press