(CNN) -- Switzerland will not send Oscar-winning filmmaker Roman Polanski to the United States to face sentencing for child sex charges, the Ministry of Justice announced Monday.

He is now free, the ministry said.

Polanski pleaded guilty in Los Angeles, California, in 1977 to having unlawful sex with a 13-year-old girl, but fled to Europe before he was sentenced.

He was arrested in Switzerland last year and had been fighting extradition since then.

Switzerland was not making a decision about the severity of the charge or whether Polanski was guilty, Justice Minister Eveline Widmer-Schlumpf said.

"It's not about qualifying the crime. That is not our job. It's also not about deciding over guilt or innocence," she said.

The Swiss rejected the American request because the United States did not supply all the legal records Switzerland requested, and because Polanski had a reasonable right to think he would not be arrested if he visited the country, she said.

U.S. prosecutors cannot apply again to Switzerland to have Polanski extradited, she said, but could apply to other countries to detain and extradite him.

"We are deeply disappointed," said U.S. Assistant Attorney General Lanny Breuer, head of the Justice Department's criminal division. "We thought our extradition request was supported by the facts. We're going to review our options."

Assistant Secretary of State P.J. Crowley also expressed disappointment, saying that the United States "believes that the rape of a 13-year-old child by an adult is a crime" and would continue to pursue justice in the case.

Asked about comments by the Swiss attorney general that suggested technical errors in the U.S. extradition request, Crowley said: "A 13-year-girl was drugged and raped by an adult -- this is not a matter of technicality."

Polanski was 43 at the time he had unlawful sex with the girl. He is now 76.

Prosecutors dropped rape and other charges in exchange for his guilty plea.

But Polanski fled the country before he was sentenced after learning that the judge might not go along with the short jail term Polanski expected to get in exchange for his plea.

He has been a fugitive since 1978 and lived in France before his arrest.

Swiss authorities released the director from jail on $4.5 million bail in early December "pending extradition" to the United States.

Polanski's victim came forward long ago and has made her identity public, saying she was disturbed by how the criminal case had been handled.

Samantha Geimer, now in her 40s and a married mother of three, has called for the case to be tossed out.

Her attorney, Larry Silver, reiterated her position in December , saying details of the case harm her every time the story is in the news.

Defense attorneys also argued that prosecutors are ignoring the victim's wishes.

Polanski's attorney, Chad Hummel, has been pushing for Polanski to be sentenced without having to return to Los Angeles.

Prosecutors have vigorously opposed sentencing him in absentia.

In court papers filed in January, Deputy District Attorney David Walgren stated the reasons in no uncertain terms.

"The defendant is a fugitive," Walgren wrote. "A fugitive child rapist, who for 32 years has made a mockery of our criminal justice system, should not be given the power or authority to request anything of this court until he, the criminal, acknowledges this court's lawful authority by surrendering on his outstanding warrant."

Polanski won an Oscar for best director for the Holocaust drama "The Pianist," and was nominated for "Tess," "Chinatown," and the screenplay he wrote for "Rosemary's Baby."

CNN's Nadine Schmidt, Ben Brumfield, Ann O'Neill, Stephanie Chen, Elise Labott and Terry Frieden contributed to this report.