Lawyers acting for imprisoned director Roman Polanski have filed a motion today (September 29) to the Swiss Federal Criminal Court requesting his release.

Announcing the filing, the court said that “the decision will be made within the next weeks”, suggesting that Polanski was not expected to be freed until the process, including the verdict and following appeals, has been completed.

The Swiss court has to decide the legality of the US request for Polanski’s arrest although the director could seek to overturn any decision at the Federal Tribunal, Switzerland’s highest court.

Polanski was arrested in Saturday as he arrived in Switzerland to receive a lifetime achievement award from the Zurich Film Festival. He pleaded guilty to unlawful sexual intercourse in 1977 with a 13 year old girl. He spent 42 days in prison but fled to France on the day of his sentencing in 1978.

The Swiss Justice Ministry is reported to have not ruled out the possibility that he could be released on bail under strict conditions that he does not flee the country, although there is not thought to be any precedent in Swiss law.

The US has 60 days to file a formal extradition request that will then be examined by the Swiss Justice Ministry, and once approved it can be appealed at a number of courts.

Polanski has travelled widely around Europe during his exile despite claims there has been an international warrant for his arrest since 2005.

The move comes as a growing number of film-makers and industry figures, including Harvey Weinstein and Thierry Fremaux, signed a petition calling for his release.