NEW YORK (AP) – Six different types of prescription drugs were found in Heath Ledger’s apartment – including anti-anxiety medications and sleeping pills – though the cause of his death will not be known for several days after a preliminary autopsy was inconclusive, authorities said.

Ledger was found dead Tuesday, Jan. 22, by his housekeeper and a massage therapist – lying naked and face-down on his bed, police said. The pills were found in bottles in Ledger’s bedroom and bathroom, and police said the death was caused by a possible drug overdose and appeared to be accidental.

Ellen Borakove, a spokesperson for the medical examiner’s office, said the autopsy on the 28-year-old actor was inconclusive, and that more would be known in about 10 days, when more tests were completed.

A rolled-up $20 bill was also found on the floor near the Australian actor’s bed, but lab tests detected no traces of drug residue, officials said Wednesday. Police also said no illegal drugs were found in the apartment.

Among the prescription medications found were pills to treat insomnia and anxiety, and an antihistamine, according to two law enforcement officials who spoke on condition of anonymity because the investigation is ongoing. Three of the drugs were prescribed in Europe, the sources said. Ledger had recently been filming in London.

The $20 bill was found on the floor near Ledger’s bed, and New York Police Department spokesperson Paul Browne said lab tests found nothing to indicate it had been used to snort drugs.

Police said Ledger probably died Tuesday between 1 p.m. and 2:45 p.m. At 1 p.m., the housekeeper went into his bedroom to change a light bulb, saw him sleeping and heard him snoring.

At 2:45 p.m., the massage therapist showed up for Ledger’s appointment, knocked on his door and got no answer. She later noticed Ledger was unconscious and called Mary-Kate Olsen, whose number was programmed into Ledger’s cell phone, to seek advice.

Olsen said she would send over her private security. In the ensuing moments, the massage therapist realized that Ledger might be dead, and called Olsen again, and then called an ambulance. Paramedics – and Olsen’s security people – arrived minutes later.

News of the death stunned family, fans and colleagues.

“Working with Heath was one of the purest joys of my life,” said Ang Lee, who directed Ledger in Brokeback Mountain. “He brought to the role of Ennis more than any of us could have imagined – a thirst for life, for love and for truth, and a vulnerability that made everyone who knew him love him. His death is heartbreaking.”

Lee Daniels, who produced the critically acclaimed Monster’s Ball, in which Ledger starred, strongly disputed any notion that Ledger had a drug problem.

“The definition of substance abuse is really up to one’s perspective,” Daniels said. “I didn’t see him as a drug addict. I saw him as someone who enjoyed life. I know drug addicts; he was not a drug addict.”

Before moving to Manhattan, Ledger lived in Brooklyn with then-girlfriend Michelle Williams.

Speaking in Australia, Ledger’s father called the death “tragic, untimely and accidental.”

“Heath has touched so many people on so many different levels during his short life,” Kim Ledger said. “Please now respect our family’s need to grieve and come to terms with our loss privately.”

Fans left flowers and candles Wednesday outside Ledger’s apartment in the upscale SoHo neighborhood of Manhattan on Wednesday. Khaled Ali, 41, a stage manager for a Broadway show, dropped off a candle on his way to work, saying he and fellow cast members were devastated.

“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 such as 10 Things I Hate About You. Thereafter, he avoided the easy path in favor of roles that forced him to bury his Australian accent and downplay his leading-man looks: the tormented gay cowboy Ennis Del Mar in Brokeback Mountain; a drug addict in Candy; an incarnation of Bob Dylan in I’m Not There.

Playing the Joker in the upcoming Batman movie The Dark Knight, may be his final finished performance.

Ledger split last year with Williams, who played his wife in Brokeback. The two had a daughter, the now 2-year-old Matilda. The 27-year-old actress had been in Sweden shooting scenes for the upcoming film Mammoth, said Martin Stromberg, a spokesperson for film production company Memfis Film.

The actor’s personal strife was accompanied by professional anxiety. He said in a November interview that Dark Knight and I’m Not There took a toll.

“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.