Shia LaBeouf has defended his decision to have intercourse on screen for controversial director Lars Von Trier's explicit new movie, insisting, "Sex is beautiful".

I have ethics, I'm not completely out of my mind

The actor has signed up to star in The Nymphomaniac, about a young woman's sex life, and reveals he has had in-depth discussions with the maverick filmmaker about his limitations as he prepares to strip off and have real sex for the racy scenes.

He tells USA Today, "There are rules. I have ethics, I'm not completely out of my mind. But I don't think there's anything wrong with sex. Sex is beautiful if it's done right. And I wouldn't just do it for no reason... Sex is different than love, and there is a separation, and that middle gap is what the movie's about".

The Transformers star hopes the role will help him move away from big-budget blockbusters, and admits he would happily trade the money he has earned in his career for credibility and the chance to make smaller, character-driven projects.

He adds, "All I'm really trying to say in the most politically sensible way is, 'Thank you so much for giving me the opportunities, I would just like to make movies about people now.' That's it...

"If I could give the money back and get all the credibility in the world that I'm seeking, I would do it tomorrow. In a heartbeat".