Heath Ledger fans have been warned against buying movie merchandise from the new Batman film The Dark Knight  -because all no official memorabilia has been released yet.

The late actor who stars as The Joker in the upcoming movie has been the target of bogus traders selling ‘signed’ Dark Knight photos and posters to gullible movie fans.

A representative for Warner Bros. Pictures, the film studio behind the project, insisted: "There are no Dark Knight posters or memorabilia connected to the movie on sale yet. We are investigating how they have been pirated."

Ledger’s family are also infuriated at the cheek of such traders selling fake goods. A source close to the family said: "They're furious that pirates are cashing in on his death."

Heath suffered a fatal accidental overdose of prescription drugs in his New York apartment on 22 January.