Matt Damon will not be appearing in the fourth 'Bourne' movie.

The Hollywood hunk - who has played hero Jason Bourne in the first three movies of the series - will not return to the fourth instalment, titled 'The Bourne Legacy', the film's director Tony Gilroy has confirmed.

He said: "It's a completely original screenplay. This is not a reboot or a recast or a prequel. No one's replacing Matt Damon. There will be a whole new hero, a whole new chapter. This is a stand-alone project."

Discussing the project, Gilroy reveals Jason has not been killed off, paving the way for a future return for Matt.

He added to film blog Hollywood Elsewhere: "The easiest way to think of it is an expansion or a reveal. Jason Bourne will not be in this film, but he's very much alive. What happened in the first three films is the trigger for what happens.

"I'm building a legend and an environment and a wider conspiracy. The world we're making enhances and advances and invites Jason Bourne's return down the road.

"Everything you saw in the first three films actually happened, and everyone who got into will be rewarded for paying attention. We're going to show you the bigger picture, the bigger canvas. When you see what we're going and see what we're doing it'll be pretty obvious... but Jason Bourne's activities in the first three films are The Immediate trigger."

'The Bourne Legacy' is expected for release in 2012.