Johnny Depp says playing The Riddler in a new Batman movie would be a "fun gig".

The 'Pirates of the Caribbean' star admits starring alongside Christian Bale in the third movie in Christopher Nolan's film franchise is an exciting prospect.

When asked about the rumours, Depp replied: "I heard about that. It seems like it'd be a fun gig for a while, yeah."

The Riddler is a manic super-villain who baffles Batman with his cryptic criminal clues.

If Depp took the role, he would be solving Nolan's problem of how to replace Heath Ledger's The Joker following the actor's death from an accidental prescription drugs overdose in January.

It would not be the first time Depp has stepped into one of Ledger's roles.

Following the 28-year-old's death, Depp teamed up with Jude Law and Colin Farrell to replace Ledger in 'The Imaginarium of Dr. Parnassus'.

The movie sees Ledger's character Tony transported into three separate dimensions, which he accesses via a paranormal mirror belonging to a travelling theatre troupe.

Depp, Law and Farrell will each portray Tony in different realms of the fantasy epic.