Mr. Wells’s detailed description of having counseled Judge Laurence J. Rittenband on how to sentence Mr. Polanski, who pleaded guilty to one county of having unlawful sex with a minor, has been at the center of a hot legal fight over the case.

Even before Mr. Polanski was arrested last Saturday in Switzerland for possible extradition to the U. S., his lawyers had asked the Los Angeles courts to throw his case out or allow another court to review it, because of alleged corruption in the local judicial system, particularly involving the actions described by Mr. Wells on film. That matter is still pending before a California appellate court.

Chad Hummel, a lawyer for Mr. Polanski, declined to comment on Mr. Wells recantation. Sandi Gibbons, a spokeswoman for the Los Angeles county district attorney’s office, said: “Anything we have to say will be in legal pleadings or in court.”

Reached in Paso Robles, Calif., on Wednesday, Mr. Wells said he had informed the district attorney’s office of his lie several months ago, and offered to make a formal statement, though none was taken.

Mr. Wells said he was publicly recanting now, in order to clear his actions away from other issues in the Polanski case. But he also acknowledged that the conduct he described in the 2007 documentary, “Roman Polanski: Wanted and Desired,” could have triggered an action against him before the state bar. “If it happened, it would have been unethical,” Mr. Wells said.