DENVER - Pressure is mounting on the judge overseeing Kobe Bryant's sexual assault case, with prosecutors citing courthouse gaffes as a reason for seeking the indefinite delay of the NBA star's criminal trial and the father of his accuser blasting the bench for bias against the prosecution.

Prosecutors requested the delay even as they made moves to appeal a key ruling in the case, arguing to the Colorado Supreme Court that the accuser's sexual activities should not be admitted as evidence. If accepted, the appeal could delay the trial for weeks.

The legal moves came as the father of Bryant's accuser wrote a blistering letter to District Judge Terry Ruckriegle saying his family had "lost trust that we can obtain a fair trial in your court."

"It has been painfully obvious that you treat the defense as if they can do no wrong and the prosecution and my daughter's attorney as if you have something against them or this case," he wrote in a letter filed with the court on Monday and released Wednesday.

Bryant 25, has pleaded not guilty to felony sexual assault. He has said he had consensual sex with the woman, then 19, at the Vail-area resort where she worked last summer. Jury selection is scheduled to begin Aug. 27.

Experts said it was unlikely Ruckriegle will agree to a delay at such late notice. Nearly 1,000 residents have been mailed jury summonses, witnesses have been scheduled to testify, and the judge and attorneys have cleared their calendars for September, said Craig Silverman, a former prosecutor.

The request for delay, the high court appeal and the letter could indicate the victim is planning to abandon the criminal trial, legal experts speculated Wednesday.

In a court filing made public Wednesday, prosecutor Dana Easter said the recent release of closed-door testimony hurt the chances of getting a fair jury. She also said the judge has not yet decided whether the woman's mental health and medical history will be admitted as evidence, leaving prosecutors in limbo on whether to hire more expert witnesses. Easter also accused defense experts of waiting too long to turn over DNA test results.

Prosecutors filed their request for a delay on Tuesday, the same day attorneys for the accuser filed a civil lawsuit against Bryant in federal court in Denver seeking compensatory damages of at least $75,000 and unspecified punitive damages.

Prosecutors' appeal to the state Supreme Court challenges Ruckriegle's decision to allow details from the accuser's sex life in the three days before her hospital exam to be introduced as evidence. That decision is expected to allow the defense to argue she had sex with someone after Bryant but before the exam. The woman's attorney has denied that claim.