The Cesars have been overshadowed by a row over its organisers' decision to ask Roman Polanski to preside over the ceremony (AFP Photo/VALERY HACHE)

Los Angeles (AFP) - Fugitive filmmaker Roman Polanski plans to return to the United States and is seeking assurances he will do no further jail time over unlawful sex with a 13-year-old girl.

The award-winning director of "The Pianist" and "Chinatown," who has been on the run for almost 40 years, claims he reached a plea deal in the case that would keep him out of prison, his attorney Harland Braun told AFP.

Braun has written to Los Angeles County Superior Court judge Scott Gordon to unseal a secret transcript of the testimony of the prosecutor in the Polanski case, which he believes will confirm the deal.

The Paris-born director was accused of drugging Samantha Gailey -- who now uses the surname Geimer -- before raping her at film star Jack Nicholson's house in Los Angeles in 1977.

Polanski, who also has French citizenship, admitted having unlawful sex with a minor, or statutory rape, and spent 42 days in Chino State Prison before being released.

But in 1978, convinced a judge was going to scrap the plea deal and hand him a hefty prison sentence, he fled for France.

Polanski was arrested in Switzerland in 2009 on a US extradition request and spent 10 months under house arrest before Bern rejected the US order.

The United States then asked Poland to extradite Polanski in January 2015, but the country's Supreme Court ruled in December that he had served his time under the plea deal.

- 'Safe in my country' -

Braun believes the secret testimony of prosecutor Roger Gunson collected in 2010 in the US supports Polanski's claim that he had an agreement to serve just 48 days and that -- taken with the Polish decision -- it should convince the US authorities Polanski has served his time.

"After we confirm the contents, we will urge the court to recognize the Polish decision resulting from a litigation initiated by the (district attorney) and in which the DA participated," Braun told AFP.

"If the court accepts the principle of comity, Roman can come to Los Angeles and to court without fear of custody."

Polanski's French legal team told AFP the filmmaker was not intending to be present at a hearing scheduled for next week in Los Angeles to consider a request.

Polanski told the private news channel TVN24 after the Polish court had ruled in his favor that he was "happy this business is over once and for all."

"I only regret that I had to wait so long. I'll finally be able to feel safe in my own country."

Polanski, who lives in France and had been avoiding Poland because of the case, said he planned to visit his father's grave in the southern city of Krakow.

The filmmaker has been engaged in a decades-long cat-and-mouse game with US officials seeking his extradition for trial, before a global audience split between continuing outrage and forgiveness for his acts.

Born in Paris in 1933 to Polish Jewish parents who later brought the family back to their native country, he saw his parents arrested by the Nazis in Krakow's Jewish ghetto and sent to concentration camps.

- Brutal slaughter -

He roamed the countryside, trying to survive at the age of just eight, helped by Catholic Polish families, in a country occupied by German troops.

The experience lent a gripping autobiographical authenticity to his 2002 movie "The Pianist," the story of a young Jewish musician trying to evade the Nazis in occupied Warsaw.

Lured to Hollywood in 1968, Polanski shot his first big international hit, "Rosemary's Baby," starring Mia Farrow as an expecting mother carrying the devil's spawn.

But tragedy struck the following year when his heavily-pregnant wife, the model and actress Sharon Tate, and four friends were brutally slaughtered in the director's mansion by cult leader Charles Manson and his followers.

Devastated, Polanski left for Europe, then returned to achieve arguably his greatest triumph in 1974 with "Chinatown" -- an atmospheric film noir starring Jack Nicholson nominated for 11 Oscars.

He has avoided the US since the statutory rape case -- not even returning to accept the Oscar for "The Pianist" -- and jousted with the Justice Department for years after.

Geimer herself called for the charges to be dropped, complaining that in dogging Polanski for so long, antagonists had made him her co-victim in a case she wanted to put behind her.

"The publicity was so traumatic and so horrible that his punishment was secondary to just getting this whole thing to stop," Geimer told CNN in 2003.

Polanski wants to visit Tate's grave in Los Angeles, the celebrity news website TMZ reported. He has also not been able to visit his daughter in London, it said.