Heath Ledger, 28, died of accidental intoxication brought on by his abuse of a cocktail of prescription drugs, the toxicology tests revealed.

"Mr Heath Ledger died as the result of acute intoxication by the combined effects of oxycodone, hydrocodone, diazepam, temazepam, alprazolam, and doxylamine," the New York's chief medical examiner's office said in a statement. "We have concluded that the manner of death is accident, resulting from the abuse of prescription medications," it added.

This means, in layman's terms, that Heath Ledger took the painkillers OxyContin and Vicodin, the anti-anxiety drugs Valium and Xanax and the sleep aids Restoril and Unisom all at once. He acknowledged that he had sleep problems in at least an interview and that sleeping pills did little to help him rest.

"Today's results put an end to speculation, but our son's beautiful spirit and enduring memory will forever remain in our hearts," said Ledger's father Kim in a statement quoted by AFP. "While no medications were taken in excess, we learned today the combination of doctor-prescribed drugs proved lethal for our boy," he said, adding "we respectfully request the worldwide media allow us time to grieve privately."

Heath Ledger’s family arrived in Australia on Tuesday to attend the private funeral that will take place in the actor’s hometown of Perth. Although funeral arrangements are being kept secret, it is believed that the actor, whose premature death on Jan. 22 shocked fans around the world, will be buried in the family plot, near his grandparents, at Perth's Karrakatta Cemetery, sometime this week.

Private memorial services for actor Heath Ledger took place at the G’Day USA Australia Day Ball in Manhattan and at the Beverly Hills Hotel in California on Jan. 26, while his body was still in the United States.

The 28-year old actor was found naked and dead in his apartment in Manhattan around 3:26 p.m. on Tuesday by his maid. A rolled-up 20 dollar bill near the body had tested negative for drugs.

He was an Academy Award-nominated actor for his controversial role as cowboy Ennis Del Mar in 2005 “Brokeback Mountain.” Former fiancée Michelle Williams, the mother of his two-year-old daughter Matilda, spoke only days after the tragic death, saying her heart was broken and requesting privacy for those in mourning. Ledger and Williams began their romantic relationship while filming Ang Lee’s Academy Award-nominated drama “Brokeback Mountain.” Both actors as well as co-star Jake Gyllenhaal were nominated.

The Hollywood community allied in anger last week after a dubious “drug video” with Ledger was publicized by two U. S. entertainment TV shows. Plans of broadcasting it were nixed, with the involved shows making a point of explaining that the late actor was never shown consuming drugs in the footage.

Production on Terry Gilliam's indie film, which Ledger started shooting in London before he died, has been halted indefinitely, Greg Chambers, business manager for the craft union ACFC West (Association of Canadian Film Craftspeople), told People. About 100 crew members have been dismissed until producers discuss their options, whether to recast the film or scrap it entirely.

Ledger, who previously worked with Gilliam on 2005's "The Brothers Grimm," was the film's biggest star, and a key factor in the British-Canadian production's financing. "The Imaginarium of Doctor Parnassus," which follows a traveling impresario's efforts to save his daughter from the devil, was more or less counting on Ledger’s appearance in the movie in raising the finance.

In 2007 he was one of the six actors who portrayed Bob Dylan in the movie “I’m Not There.” He has just finished working in the sequel of “Batman Begins”, “The Dark Night” in which he portrayed the Joker. The movie is set to debut on July 18, 2008.