KEY POINTS:
Actor Heath Ledger did not kill himself, according to his father.
Ledger was found dead in his Soho residence in New York City today.
Ledger's family, including father Kim and mother Sally and sister Kate spoke to reporters in Perth this afternoon.
"We, Heath's family can confirm the very tragic, untimely and accidental passing of our dearly loved son, brother and doting father of Matilda," his father said.
"He was found peacefully asleep in his New York apartment by his housekeeper. He was down to earth, generous, kind-hearted, life-loving, unselfish, individual (and) extremely inspirational to many."
"We would like to thank our friends and everyone around the world for their well wishes and kind thoughts at this time," Mr Ledger said.
"Heath has touched so many people on so many different levels during his short life but few had the pleasure of truly knowing him."
Celebrity news website TMZ.com has reported Ledger was sick with pneumonia when he died.
New York police said they could not confirm Ledger was suffering from pneumonia.
"This is the first I'm hearing that," Lieutenant John Grimpal, from the New York Police Department, told Macquarie Radio.
"The medical examiner, once he or she conducts an autopsy, will determine exactly the cause of death."
Ledger was discovered naked and unconscious near his bed by a housekeeper at at 3.35pm (9.35am NZT) when a masseuse arrived for a scheduled appointment.
TMZ reports the actor was in full cardiac arrest by the time emergency services arrived at the apartment. They attempted to perform CPR on him, but were unsuccessful. He was pronounced dead at the scene.
Police have confirmed sleeping pills - both prescription medication and nonprescription were found near Ledger's bed in the apartment.
Michelle Williams, Ledger's former fiancee and mother of their two-year-old daughter Matilda, is reportedly devastated to hear of his death. She is believed to be on her way to New York.
A police spokesman initially told media that the apartment Ledger was found in was owned by the actress Mary-Kate Olsen, but later retracted his statement and said that was not the case.
Fellow Australian actress Nicole Kidman called Ledger's death a 'tragedy' in a statement to Us Magazine.
"What a tragedy," Kidman said. "My heart goes out to his family."
Ledger dated Kidman's close friend, actress Naomi Watts, between 2002 and 2004.
Alan Horn, President and CEO of Warner Bros, the producers of the upcoming Batman movie The Dark Knight, in which Ledger stars, released this statement to TMZ:
"The studio is stunned and devastated by this tragic news. The entertainment community has lost an enormous talent. Heath was a brilliant actor and an exceptional person. Our hearts go out to his family and friends."
The 28-year-old Australian-born Oscar nominee first shot to fame in 1999 in the teen comedy 10 Things I Hate About You.
In 2005, he was nominated for an Oscar for his portrayal of a gay cowboy in Brokeback Mountain.
New York Times critic Stephen Holden decribed the role as "A great screen performance, as good as the best of Marlon Brando and Sean Penn."
His latest role was as The Joker, in the yet-to-be-released Batman film The Dark Knight.
The actor split from his girlfriend Michelle Williams - with whom he had a two-year-old daughter, Matilda Rose - in August of last year.
Ledger had a turbulent relationship with paparazzi photographers who he said hounded him. In 2004 he allegedly spat at and assaulted a photographer in Sydney. In retaliation a photograper at the Sydney premiere of Brokeback Mountain squirted Ledger in the face with a water pistol.
Ledger's other film credits included A Knight's Tale, The Patriot, Casanova, Ned Kelly, Lords of Dogtown and Monster's Ball. He recently appeared in I'm Not There, one of several actors playing a role representing Bob Dylan and was currently working on the movie The Imaginarium of Doctor Parnassus, directed by Terry Gilliam and in which he was to star alongside Christopher Plummer and Tom Waits.
Australian Prime Minister Kevin Rudd has paid tribute to Ledger, saying the country had 'lost one of our nation's finest actors'.
Mr Rudd described as a tragedy the loss of the 28-year-old actor.
"It was with great sadness that I have learned of the passing of Heath Ledger," he said.
"It is tragic that we have lost one of our nation's finest actors in the prime of his life.
"Heath Ledger's diverse and challenging roles will be remembered as some of the great performances by an Australian actor."
The director of Ledger's last Australian movie, Candy, Neil Armfield, told Australia's ABC Radio he was "incredibly saddened" to hear of the 28-year-old's death.
"He was a young boy in many ways, still a boy when he left Perth and got into this whirlwind of his career," Armfield said.
- NZHERALD STAFF/AGENCIES