The film-maker is currently under house arrest
A judge has ruled that secret testimony given by the original prosecutor in Roman Polanski's sex case 33 years ago will remain sealed.
Polanski's lawyer Chad Hummel argued Roger Gunson's testimony could help Swiss authorities to decide whether or not to extradite Polanski.
But Superior Court judge Peter Espinoza noted that Swiss officials had ruled the transcripts were "irrelevant".
Film director Polanski, 76, is under house arrest in his Swiss chalet.
He is facing a US arrest warrant over his conviction for unlawful sex with a 13-year-old girl in 1977.
The director, who was originally charged with six offences including rape and sodomy, pleaded guilty to unlawful sex following a plea bargain.
But he left the US in 1978 before he could be sentenced and has never returned.
'On a platter'
"We continue to be bogged down in the question of whether he (Polanski) will return," said Judge Espinoza in court on Monday.
Mr Hummel also argued that Mr Gunson's testimony could be crucial in proving Polanski's claim of misconduct by the original judge, who is now deceased.
But Judge Espinoza said the only circumstance in which the material would become public was if Polanski returned to the US for a hearing and Mr Gunson was unavailable to testify in person.
Polanski broke his silence earlier this month to decry the US for seeking his extradition.
"I can no longer remain silent because the United States continues to demand my extradition, more to serve me on a platter to the media of the world than to pronounce a judgment concerning which an agreement was reached 33 years ago," he wrote in a statement.