Ledger, who is earning posthumous raves for his portrayal of the Joker in the new Batman blockbuster, "The Dark Knight," died in January of an accidental lethal combination of prescription drugs.

He had been working on Gilliam's fantasy film, "Parnassus," at the time of his death and Gilliam subsequently hired actors Jude Law, Johnny Depp and Colin Farrell to play different aspects of the character Ledger had begun. The footage Ledger shot will remain in the film, Gilliam said.

"I've seen it and it works and it's great," Gilliam told the BBC. "It's the last chance to see Heath and he's brilliant. (Filming) stopped for a bit until the three heroes as they're now known -- Jude Law, Johnny Depp and Colin Farrell -- came to the rescue and finished off Heath's part. So you ended up with four actors playing one character."