Christian Bale has labelled Heath Ledger's work as The Joker in The Dark Knight as an "iconic" performance.

The Batman sequel had its world premiere in New York City on Monday night, with Ledger's co-stars Bale and Sir Michael Caine in attendance, alongside the late actor's family.

Ledger was found dead in his Manhattan apartment on January 22nd after an accidental overdose of prescription medication.

He has since been widely tipped to receive a posthumous Oscar for his role as the comic book villain and the Australian actor "steals the movie", Bale admitted.

"Working with Heath was fantastic," he explained. "He was a hell of a talent and created a joker that's very iconic and one that will become a classic portrayal of the ages."

Sir Michael, 75, who reprises his Batman Begins role as Alfred in The Dark Knight, told People magazine of the "intensity and ferocity" of Ledger's performance.

"But when we were sitting down between takes, he was completely ordinary," he revealed. "He wasn't preparing himself or saying 'Please leave me alone, I've gotta do this.' Instead he was talking to me.

"We would sit and chat and have a cup of coffee, then suddenly they'd say, 'We're ready, Heath,' and he'd go straight into The Joker," The Italian Job star continued.

"His energy was astonishing, especially when it came from this kind of calm. He's certainly the best villain I've ever seen."

The Dark Knight is released on July 25th.

15/07/2008 08:52:21