The organizers said in a statement that Polanski was detained by police Saturday in relation to a 1978 U.S. request, without giving details. [break]
Zurich police spokesman Stefan Oberlin confirmed Polanski´s arrest, but refused to provide more details because he said it was a matter for the Swiss Justice Ministry.
Ministry spokesman Guido Balmer declined to comment.
Polanski fled the United States in 1978, a year after pleading guilty to unlawful sexual intercourse with a 13-year-old girl.
The 76-year-old director of such classic films as "Chinatown" and "Rosemary´s Baby" recently sought dismissal of his case on grounds of misconduct by the now-deceased judge who had arranged a plea bargain and then reneged on it.
Polanski has lived for the past three decades in France, where his career has continued to flourish. He received a directing Oscar in absentia for the 2002 movie "The Pianist."
Festival organizers said Polanski traveled to Switzerland to receive an award for his lifetime of work as a director.
They said Polanski´s detention had caused "shock and dismay," but that they would go ahead with Sunday´s planned retrospective of the director´s work.
Judge refuses to end Roman Polanski sex assault case