Noted filmmaker Roman Polanski edited his new film The Ghost Writer while living in a jail in Switzerland, revealed the movie's stars Pierce Brosnan and Ewan McGregor. The Oscar-winning director was arrested and detained on a 32-year-old sex crime charge in September last year before the new film had been completed.

The 76-year-old filmmaker, who is now under house arrest at his chalet in Switzerland, had to make arrangements to complete the film during imprisonment, CNN online reported.

"He would be in his nine-foot by four-foot cell, edit the movie and give it to the warden. The warden would give it to his lawyer (who would) then give it to the editor," said Brosnan, who stars as a former British Prime Miniter in the film.

"I think he had no other option," added McGregor, who plays the lead in the political thriller. At one point, McGregor feared that another director would be commissioned to complete Polanski's film.

"I thought it would be a great pity to be in the only Polanski film that wasn't finished by Polanski," he said. Polanski, who is fighting extradition to the US over the case of having sex with a minor, was unable to attend the recent premiere of the film at the Berlin Film Festival in Germany where he won the Silver Bear for Best Direction.