Insomniac Ledger found surrounded by sleeping pills

Tributes were paid to Hollywood star Heath Ledger today as speculation grew that he died from an accidental overdose of sleeping pills.

The 'Brokeback Mountain' star, 28, revealed in one of his last interviews that he suffered from insomnia due to the stress of work.

He confessed to taking one Ambien sleeping pill after another while filming the new Batman movie 'The Dark Knight'.

“Last week I probably slept an average of two hours a night. I couldn’t stop thinking. My body was exhausted and my mind was still going,” he told the New York Times in November.

He told the newspaper that taking one pill had no effect. He took a second and fell into a stupor, only to wake an hour later with his “mind still racing”.

The Australian actor was found dead in his New York apartment yesterday, surrounded by sleeping pills.

Ledger spent his last days shooting a film in London.

He was working on the new Terry Gilliam project 'The Imaginarium of Doctor Parnassus' and gave no outward signs of being troubled, sources said.

A smiling Ledger was photographed on set on Saturday, the last day of filming before production moved to Vancouver.

An insider on the film said: “This news has come as a terrible shock. There were no problems we were aware of.

“Heath was very private and everyone working on the film was respectful of that. He didn’t chat much on set but he was always polite to the cast and crew.

“The character he played was enigmatic – a bit like the actor himself. He wasn’t keen on all the publicity that goes with a film and just wanted to concentrate on his acting.”

The 'Imaginarium of Doctor Parnassus' is a fantasy adventure about a travelling theatre group, also starring Christopher Plummer and Tom Waits.

Supermodel Lily Cole played Ledger’s love interest.

Ledger filmed in London throughout December and had a 10-day Christmas break in his native Australia before returning to the set.

He recently completed filming his role as the Joker in 'The Dark Knight', set for release in July.

The film’s makers, Warner Bros, said in a statement: “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.”

Michael Caine, his co-star in the Batman film, recently spoke of Ledger as an extraordinary talent.

“I tell you the big surprise in the new Batman – Heath Ledger as the Joker. He’s fantastic,” he said in October.

The role was previously played by Jack Nicholson and Michael said of Ledger’s performance: “He’s gone in a different direction than Jack. Jack was like a really scary old, nasty old uncle with a funny face. Heath is like the most murderous psychopath you’ve ever seen on the screen.”

Among the stars paying tribute today were fellow Australians Nicole Kidman and Mel Gibson.

“What a tragedy. My heart goes out to his family,” said Kidman.

Gibson said: “He was just taking off and to lose his life at such a young age is a tragic loss. My thoughts and prayers are with him and his family.”

An autopsy will be held later today.