Sam Mendes is the "front-runner" to direct a 'Wizard of Oz' prequel.

The British filmmaker - who has now found himself out of work due to the suspension of 'Bond 23' - is Disney's favourite to direct 'Oz the Great and Powerful', a retelling of the classic tale from the perspective of the Wizard.

Robert Downey Jr. is believed to be the actor wanted for the lead role in the movie, which would reveal his back-story as part of a travelling circus which arrives in Oz, Production Weekly reports.

'Romeo Must Die' screenwriter Mitchell Kapner has created The Script and 'Alice in Wonderland' producer Joe Roth will also work on the project.

Oscar-winning director Mendes has a strong back-catalogue of work, which includes 'American Beauty', 'Jarhead' and 'Revolutionary Road', but none in the fantasy genre.

'Oz the Great and Powerful' does not yet have a planned production or release date.