The acclaimed filmmaker is considered a convicted felon and a fugitive by authorities in Los Angeles, and the United States is seeking his extradition for having sex in 1977 with a 13-year-old girl. He was arrested by the Swiss on Sept. 26 as he arrived in Zurich to receive a lifetime achievement award from a film festival.
"The court considered the risk that Roman Polanski might flee if released from custody as high," the federal court said. "The bail offered by the appellant does not meet in its form the requirements set out by the law."
Still, the tribunal in the southern Swiss city of Bellinzona left open several possibilities for Polanski to challenge its verdict in what is expected to be a lengthy legal battle over his extradition.
Polanski has 10 days to appeal the decision on his release to Switzerland's highest tribunal. He can also continue attempts to persuade the Swiss Justice Ministry to release him. More court proceedings are expected after Washington files its formal extradition request, which it has until Nov. 25 to submit.
The director of such film classics as "Rosemary's Baby" and "Chinatown" was accused of plying the underage girl with champagne and a Quaalude sedative pill during a modeling shoot in 1977, and raping her. He was initially indicted on six felony counts, including rape by use of drugs, child molesting and sodomy.
He pleaded guilty to the lesser charge of unlawful sexual intercourse. In exchange, the judge agreed to drop the remaining charges and sentence him to prison for a 90-day psychiatric evaluation.
However, he was released after 42 days by an evaluator who deemed him mentally sound and unlikely to offend again.
The judge responded by saying he was going to send Polanski back to jail for the remainder of the 90 days and afterward he would ask Polanski, a dual French-Polish citizen, to agree to a "voluntary deportation." Polanski then fled the country on Feb. 1, 1978, the day he was scheduled to be sentenced to the additional time.
Since then, Polanski has lived in France, which does not extradite its own citizens.
In its 17-page verdict, the Swiss court said Polanski offered to surrender his travel documents and submit himself to daily police checks. Those measures were seen as insufficient to prevent his flight because he could always obtain a new passport or even travel to his French home without papers.
The Swiss court was also concerned that Polanski could leave Switzerland and avoid the extradition process if he fled by helicopter or private airplane.
Lawyers for Polanski also offered up the director's Gstaad chalet as collateral, saying it represented more than half of his personal wealth and that it would definitely guarantee his remaining in the country because he has two children he must support through school.
The court, however, sided with Swiss authorities who said even the large bail offer provided insufficient security against flight, and should be made in cash.
The Swiss Justice Ministry said it would examine any new request Polanski submits and evaluate whether it represents a "concrete, realizable" offer as the court ruling suggests. But, spokesman Folco Galli reiterated that detention is only lifted in exceptional cases. "The point of imprisonment is to ensure that Switzerland can fulfill its treaty obligations on extradition," Galli told The Associated Press. "He can always ask again to be released. But detention is the rule."