Gerard Butler has joked he's grateful Ralph Fiennes was in his new film as it put co-star "affair" rumours to rest.

The Hollywood pair appear in Coriolanus a big screen adaptation of the Shakespeare play that Ralph also directed.

Gerard enjoyed tackling a different role to the romantic comedies he's appeared in in recent years, including The Bounty Hunter starring Jennifer Aniston.

The pair were romantically linked while shooting the film.

Gerard says filming Coriolanus was a completely different experience.

"It was nice to be able to perform opposite somebody that the press weren't saying I was having an affair with," he laughed in an interview with Shortlist magazine.

"To be able to walk around a beautiful country like Serbia without paparazzi hiding under cars was exceptionally refreshing."

Gerard tackled some high octane fight scenes in the film. The 42-year-old star is no stranger to muscle-clad roles, having shot 300 and Law Abiding Citizen.

Gerard drew on his past combat experience to get into fighting mode.

"I did have a big fight sequence with Ralph and, although it's not like he hasn't dealt with action before, I definitely felt I had more experience [in that area]," he explained.

"Originally the fight was a little too choreographed and we both thought that it needed that rawness. Just looking at someone and thinking, I want to tear your eyes out, bite your nose off and rip your arms from your sockets.'

"That's what we got, but it was tough."