Polanski undergoing medical treatment: lawyer

Polish director Roman Polanski attends a news conference for the film ''Chacun son Cinema'' at the 60th Cannes Film Festival May 20, 2007.

GENEVA (Reuters) - Film director Roman Polanski, arrested in Switzerland three weeks ago to face extradition in a U.S. sex case, has been moved from jail for medical treatment, his French lawyer said on Saturday.

"All I know is that he has been taken from prison for medical attention. I don't know where he is or when he will be returned to prison," French lawyer Herve Temime told Reuters.

He said he did not have any other details.

Temime said last week after visiting Polanski in a Zurich jail that he was depressed and tired and expressed concern about his medical condition.

Polanski, 76, was arrested in relation to the U.S. case involving sex with an underage girl dating back over 30 years, when he arrived in Switzerland on September 26 to collect a life-time achievement award at a Swiss film festival.

Polanski, who holds French and Polish citizenship, pleaded guilty to having sex with a 13-year-old girl in 1977 and spent 42 days in prison undergoing psychiatric tests.

However, he fled the United States before the case was concluded because he believed a judge would sentence him to up to 50 years behind bars despite a plea agreement for time already served.

Polanski, who won the best director Oscar for 2002 Holocaust film "The Pianist," was also accused of giving drugs and alcohol to the girl.

Folco Galli, spokesman for Switzerland's Federal Office of Justice, declined to comment on whether the film-maker had been moved to hospital, or on the state of his health.

"He is still in detention. If necessary he has all the medical care (needed). It can be in prison or in hospital, in general," he told Reuters.

U.S. authorities have up to 60 days to make a firm extradition request. U.S. judicial sources have said the complex extradition process could take years if Polanski challenges it.

(Reporting by Jonathan Lynn; Editing by Angus MacSwan)