Roman Polanski's lawyers vowed to fight his extradition over a 32-year-old child sex case, amid reports they may have sparked his arrest by suggesting that US prosecutors were not serious about nabbing the famed film director.

Support from the movie industry for the 76-year-old Polish-French Oscar winner grew as top film directors declared themselves "astonished" at his arrest in Zurich for the 1977 case.

"Filmmakers in France, in Europe, in the United States and around the world are dismayed by this decision," said a petition organized by SACD, which represents performance and visual artists.

French Foreign Minister Bernard Kouchner said the case was a "bit sinister" adding he had asked the United States to drop the charges.

Polanski, who achieved global acclaim for movies such as 'Rosemary's Baby', 'Chinatown' and 'The Pianist', was detained as he arrived on Saturday to receive a lifetime achievement award at the Zurich film festival.

Swiss authorities said they were awaiting an extradition request from the United States over the case in which he admitted having sex with a 13-year-old girl. The victim has since joined defence lawyers in urging for the case to be dismissed.

Los Angeles prosecutors confirmed Monday they would file a warrant seeking Polanski's return to the United States, noting they had 40 days to prepare it.

'Extravagant circumstances'

But Polanski's French lawyer, Herve Temime, said the director rejected any prospect of extradition.

"Given the extravagant circumstances of his arrest, his Swiss lawyer will ask without delay for him to be released, possibly under certain conditions," a statement from Temime added.

Kouchner said he was working with Polish counterpart Radek Sikorski to help Polanski and that they had jointly written to US Secretary of State Hillary Clinton to ask for the charges to be dropped.

"This affair is frankly a bit sinister. Here is a man of such talent, recognized worldwide, recognised especially in the country where he was arrested. This is not nice at all," Kouchner told France-Inter radio.

But the State Department said Monday it would not wade into the row.

Polanski fled the United States in 1978 before sentencing on a charge of unlawful sexual intercourse with a minor. He has never returned, even missing the Oscar award for 'The Pianist' in 2003.

Temine said Polanski visits Switzerland often and owns a chalet in Gstaad where he spent three months this year.

Switzerland says Polanski is being held under an international alert issued by the United States in 2005. As Polanski can launch several appeals, a final extradition decision could take weeks or months, legal experts said.

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