Johnny Depp is in talks for 'Oz: Great and Powerful'.

Robert Downey Jr. was initially expected to play the lead role in the prequel to the 'Wizard Of Oz' story - directed by Sam Raimi - but has now passed with Johnny wanted by film bosses.

The movie tells the tale of a young illusionist who is forced to flee a travelling circus and ends up in the land of Oz, which is run by two wicked witches.

Joe Roth is producing the project, the set of which is already being constructed by Disney.

However, doubts have been raised as to whether there would be enough time for Johnny - soon to be seen in 'Pirates Of The Caribbean: On Stranger Tides' - to work on the movie, as he has a number of films coming up including 'The Lone Ranger' and 'Dark Shadows' with Tim Burton.

'Oz: Great and Powerful' is the second film project Robert has pulled out of recently, having already passed on Alfonso Cuaron's 'Gravity'.