Roman Polanski staged a special screening of his newest movie "The Ghost Writer" while under house arrest in Switzerland - and he's delighted with the film.

The embattled director will not be allowed to attend the political thriller's premiere at the Berlin Film Festival in Germany on Friday so he held a showing at his chalet in Gstaad - and was impressed with the finished product.

Robert Harris, who wrote the screenplay, tells Britain's Daily Telegraph, "I don't know if he is disappointed not to be able to attend the premiere. I imagine he has been to quite a few premieres in his time.

"He was very happy with it, which was wonderful, but of course I am hugely biased."

The Oscar-winning filmmaker pleaded guilty to a charge of unlawful sex with a 13-year-old girl in 1977, but fled the States before his sentence could be passed.

He was held by officials in Zurich last year and placed under house arrest in Switzerland. Last month, a Los Angeles judge ruled he must return to the U.S. to face sentencing.

The director refused to allow his legal woes to disrupt editing of The Ghost Writer - he completed post-production on the film while under house arrest.