Polanski's attorneys have asked a judge to unseal testimony taken earlier this year by the original prosecutor handling the case, Roger Gunson. They have said it will help their efforts to fight Polanksi's extradition from Switzerland, where he remains under house arrest.
Deputy District Attorney David Walgren wrote in Thursday's filing that the request should be denied because Polanski has repeatedly refused to return to Los Angeles for sentencing.
He said allegations of misconduct in the case can and should be dealt with at Polanski's sentencing.
A hearing on Polanski's motion is scheduled for Monday afternoon.
A phone message left for one of Polanski's attorneys, Chad Hummel, was not immediately returned.
Gunson testified in a closed session in February. According to descriptions in court filings by Polanski's attorneys, Gunson testified that in 1977 he tried to challenge now-deceased Superior Court Judge Lawrence Rittenband but his supervisors prevented him from filing it after they consulted with the judge.
Gunson wanted Rittenband disqualified from the case because of misconduct, the filings state.
The testimony was taken in case Gunson, now retired, is unavailable to testify at a later hearing.
Walgren also blasted comments by Polanski's attorneys that prosecutors' requests to Swiss authorities for the director's extradition contain false and incomplete statements.
The allegations are "completely baseless and reckless allegations," Walgren wrote.
Los Angeles authorities want the Oscar-winning director returned to face sentencing on a charge he had unlawful sexual intercourse with a 13-year-old girl in 1977.
He fled the United States in 1978 on the eve of sentencing after Rittenband made private remarks that he intended to renege on a sentencing agreement reached on Polanski's case.
Polanski was arrested seven months ago as he arrived in Zurich to receive a lifetime achievement award at a film festival. He released his first public comments on the case over the weekend, saying efforts to return him to Los Angeles were meant largely to serve him "on a platter to the media."