LOS ANGELES - WHEN the new Batman movie The Dark Knight began screenings last month before its US debut on Friday, some moviegoers saw Heath Ledger as an instant Oscar candidate as the deranged villain, The Joker.

But Oscar watchers and veteran critics say the joke may be on fans creating mostly Internet-based buzz because an Academy Award for the Australian actor, who died of an accidental drug overdose in January, would be a rare event.

Only one actor has won an Oscar after death, Peter Finch for 1976's Network. Dark Knight is the type of comic book, action adventure that Oscar voters generally do not favour and there are many movies to see later this year, the experts said.

'All this Oscar talk is a phenomenon of the Internet age that I like to call 'a wish-fulfillment rumour.' If people say it often enough, they think it will happen,' said Leonard Maltin, film critic for TV program Entertainment Tonight.

'That's not to say it might not happen,' he said, citing a 'great performance' by Ledger. 'But I assure you that the people who are spreading all this are neither Oscar voters nor (Hollywood) movers and shakers.'

Tom O'Neil, a columnist for award-watching website The Envelope.com, said 'it really looks good' for a nomination but was 'a long shot' to win.

Hollywood has a long history of seeing big stars - James Dean, Marilyn Monroe and Bruce Lee among them - appearing in high-profile films released after their untimely deaths.

O'Neil said that when Finch died, Hollywood was in the middle of Oscar season and also in shock. Prior to that, Robert De Niro was sweeping the critics' awards for Taxi Driver. Veteran Oscar watcher O'Neil also sees parallels between the truncated careers of Ledger and James Dean.

'Like Heath, James Dean was a heartthrob star who was considered a serious actor, who died tragically young,' O'Neil said. 'He was nominated twice posthumously, for East of Eden and Giant, and he lost both times.'

Even the legendary Spencer Tracy was ignored by the Academy of Motion Picture Arts and Sciences, which gives out the Oscars, after he died in 1967 just as Guess Who's Coming To Dinner? was coming. And he was the front-runner, O'Neil said.

Tracy's co-star Katharine Hepburn did win best actress for Guess Who's Coming To Dinner? 'That's how reluctant Oscar voters are to hug the dead,' O'Neil said.

'These awards are all about hugs and there's something creepy about embracing the dead.' -- REUTERS