James Cameron has insisted Matt Damon was never offered the lead role in Avatar

James Cameron has insisted Matt Damon "was never offered" the lead role in Avatar.

The Good Will Hunting star has previously claimed he "turned down" a lot of money by walking away from the part in the 2009 fantasy film - which ended up being played by Sam Worthington - but the director is adamant that although the pair spoke about the possibility of getting Damon involved, he was never given an official offer.

Cameron told The Hollywood Reporter: "He was never offered the part. I can’t remember if I sent him the script or not. I don’t think I did? Then we wound up on a call and he said: 'I love to explore doing a movie with you. I have a lot of respect for you as a filmmaker. [Avatar] sounds intriguing. But I really have to do this Jason Bourne movie. I’ve agreed to it, it’s a direct conflict, and so, regretfully, I have to turn it down.'

"But he was never offered. There was never a deal. We never talked about the character. We never got to that level. It was simply an availability issue."

In a video that has been circulating online, Damon opened up about his flirtation with Avatar and claimed he turned it down because he was busy making the first Bourne movie - 2002's The Bourne Identity.

He said: "Jim Cameron called me - he offered me 10 per cent of Avatar. You will never meet an actor who turned down more money than me …

"I was in the middle of shooting the Bourne movie and I would have to leave the movie kind of early and leave them in the lurch a little bit and I didn’t want to do that …

"[Cameron] was really lovely, he said: ‘If you don’t do this, this movie doesn’t really need you. It doesn’t need a movie star at all. The movie is the star, the idea is the star, and it’s going to work. But if you do it, I’ll give you 10 per cent of the movie'."

Avatar grossed $2.9 billion following its release in 2009 making it one of the most lucrative movies of all time and Damon could have potentially earned millions from a 10 per cent stake.

However, Cameron is adamant the actor would never have been offered that kind of deal. He added to The Hollywood reporter: "Now what he’s done is he’s extrapolated 'I get 10 per cent of the gross on all my films'.

"And if, in his mind, that’s what it would’ve taken for him to do Avatar, then it wouldn’t have happened. Trust me on that.

"So he’s off the hook and doesn’t have to beat himself up anymore. Matt, it’s okay, buddy! You didn’t miss anything."

The moviemaker concluded: "So all respect to Matt. I’d love to work with him someday. But that never happened. It was a conflation of different things that were happening."