Roman Polanski's lawyer has asked a Los Angeles judge to unseal testimony given by a former prosecutor who handled the fugitive director's sexual assault case.
It is Polanski's latest bid to bring an end to case that has been hanging over him for nearly 40 years.
Harland Braun wrote the letter to the judge, made public on Thursday, asking him to unseal the letter because it is crucial to attempts to resolve Polanski's case.
The Academy Award-winning director pleaded guilty in 1977 to unlawful sex with a 13-year-old girl but fled to France in 1978 when the now-deceased judge in the case suggested in private remarks that he would renege on a plea bargain and sentencing agreement.
Los Angeles prosecutors have repeatedly sought Polanski's extradition but have been rebuffed by courts in Switzerland and Poland, two of the countries where the Oscar winner has been able to safely travel.
The director has alleged that he was mistreated by a judge and prosecutors, but subsequent judges have ruled the Oscar winner must return to Los Angeles for the case to be resolved.
Mr Braun's letter seeks the unsealing of testimony from retired deputy district attorney Roger Gunson, who handled Polanski's case.
Mr Gunson gave the testimony over three days in 2010 in case he was unable to testify at any future proceedings in the case.
Mr Braun contends Mr Gunson's testimony might help Polanski's argument that he has already served his time in the 1977 case by spending more than 300 days in jail and house arrest in Switzerland during a failed extradition effort in 2010.
Los Angeles Superior Court Scott Gordon, the presiding judge over criminal matters in Los Angeles County, set a hearing for February 24.
Polanski will not attend, Mr Braun said.
Switzerland refused to extradite Polanski because it was not allowed to review Mr Gunson's testimony.
Polanski's lawyers sought to unseal the testimony, but prosecutors objected to unsealing the transcripts, and a judge agreed.
In a 1977 deal with prosecutors, Polanski pleaded guilty to one count of statutory rape for having sex with the underage girl during a photo shoot in Los Angeles.
He was ordered to undergo a psychiatric study at the state prison in Chino, where he served 42 days.
Mr Gunson and Polanski's lawyer have said they understood from a private conversation with the judge handling the case that the time in the prison would serve as Polanski's punishment.
However, lawyers for the Polish-born director said the judge later reneged on the agreement and suggested Polanski would go back to prison. Polanski then fled to France, and his travel has been restricted to Poland, Switzerland and France ever since.
Polanski sought a dismissal of the case in 2008, but his motion was denied in a ruling that was upheld by an appellate court. A judge in 2014 rejected Polanski's request of a new hearing.
His victim, Samantha Geimer, who has publicly identified herself in court filings, interviews and a memoir, has said she forgives Polanski and has repeatedly called for the case against him to be dismissed.
Polanski won an Academy Award for best director for his 2002 film The Pianist and was nominated for 1974's Chinatown and 1979's Tess.