Attorney Gloria Allred and the accuser say they've met with authorities.
A woman who appeared in one of Roman Polanski's movies alleged Friday that the director abused her more than 25 years ago.
Attorney Gloria Allred conducted a news conference Friday with Charlotte Lewis.
Lewis, of London, appeared in Polanski's 1986 movie, "Pirates." She alleges she was victimized by Polanski when she was 16 years old.
The new accusations come as lawyers for Polanski are fighting Los Angeles prosecutors' efforts to bring him stateside to answer for a 33-year-old child rape case.
"I do believe that what she has to share with law enforcement is relevant to the ongoing investigation and to the sentencing and criminal proceedings that are in progress," Allred told CNN.
Allred said she met with a detective from the LAPD an official with the DA's office about the allegations.
"I am also a victim of Roman Polanski," Lewis said Friday. "It is very important the district attorney and the Swiss authorities be armed with this information as they decide his fate.
"All I want is justice."
Lewis said the encounter occurred in a Paris apartment.
Polanski attorney Chad Hummel was not immediately available for comment, according to City News Service.
Allred would not say whether she will pursue a civil case against Polanski. She said that even though Lewis was afraid to report her allegations to law enforcement at the time, she was now ready to testify against Polanski.
"If the court believes and gives weight to Charlotte's allegations, then Mr. Polanski deserves no compassion for the commission of his original crime to which he entered a plea, and no compassion for his age or the number of years that have passed since that crime was committed," Allred said.
The director is under house arrest in Switzerland, where he was nabbed by authorities when he came to accept a lifetime achievement award. The 77-year-old has been a fugitive from justice since 1978, when he fled from California to France just before reporting to court for sentencing.
He had pleaded guilty to having sex with a 13-year-old girl, who prosecutors said was plied with Champagne and Quaaludes and raped in a hot tub.
At the Cannes Film Festival this week, top directors signed a petition in support of Polanski. Signatories of the petition include French New Wave director Jean-Luc Godard, French actor-director Mathieu Amalric and Cannes
best director laureate Bertrand Tavernier.
The petition is posted on a website overseen by French philosopher Bernard-Henri Levy.