The defense said tests on the accuser's underpants found "other substances" from a "source" other than the Los Angeles Lakers' guard. The lawyers argue that injuries to the woman may have been caused by previous sexual partners.
The details were released in a court filing at the same time Judge Frederick Gannett rejected a prosecution request to close the remainder of a preliminary hearing to protect the 19-year-old accuser.
The hearing is to determine whether Bryant, 25, will stand trial on a charge of sexual assault. He has said the sex with the Eagle woman was consensual.
The judge admonished the news media to exercise restraint in drawing any conclusions from testimony.
"Understand you have been privy to only a portion of the information," Gannett said. The hearing then resumed with the defense questioning of the lead investigator, sheriff's Detective Doug Winters.
Last week, the hearing began with graphic testimony from Winters, who said Bryant attacked the woman from behind and raped her over her protestations.
The defense then suggested in open court that the accuser may have had sex with other men in the days before the June 30 hotel room encounter with Bryant. Prosecutors responded by asking for the hearing to be closed — a requested ridiculed by the defense in Wednesday's court filing.
"Now after damaging information about Mr. Bryant essentially unchallenged by cross-examination has been heard in open court and distributed worldwide as the prosecution intended, the prosecution now seeks to close the hearing," defense attorney Hal Haddon wrote.
"The defense never wanted this hearing to be open," he added. "Now that it has begun in open court ... Bryant's right to a fair trial will be eviscerated if the prosecution is able to achieve what it clear intended all along."
Haddon then accused prosecutors of deliberately misrepresenting blood evidence found on the panties.
"The clear implication of this testimony was that the accuser was bleeding due to the alleged sexual assault," Haddon said. Without elaborating, the filing said there was "scientific evidence from the prosecution's own laboratory which shows that other substances in those same panties were from a source other than defendant."
The defense said that evidence had been given to Gannett under seal, and it provided "compelling evidence of innocence."
Prosecutor Ingrid Bakke said Colorado's rape shield law bars the use of an alleged victim's sexual history in rape cases with few exceptions. She said defense lawyer Paula Mackey's question was a "deliberate and calculated" attempt to bring up testimony that was irrelevant at this stage.
"What was even more unexpected was her conscious misrepresentation of the evidence in order to smear the victim publicly," Bakke wrote. "The bell cannot be unrung. It will be difficult enough to overcome Ms. Mackey's misstatement of the facts."
"I think it's a fair avenue for the defense to go down because, again, they're talking about the injuries, the alleged injuries," Court TV reporter Vinnie Politan told the Early Show. "If, in fact, they have a good faith basis to believe there was other sexual activity that close in time, then it may be fair game."
Mackey and Haddon also might want to call their own witnesses, which is unusual in preliminary hearings.
"It was a tremendously effective morning for Bryant's attorneys," said CBS News legal analyst Andrew Cohen. "It's still not a likely scenario but it is beginning to look like the type of case a judge actually could dismiss at this early stage. And it's also beginning to feel like the defense senses an opportunity here to knock the case out long before trial and long before Bryant would have to testify."
Cohen reports that according to the prosecution's own witness, Bryant had no marks on him after the incident, the alleged victim went back to work and reportedly looked and acted fine after leaving Bryant's hotel room, and there was sexual material not belonging to Bryant found in the accuser's panties when she was evaluated at the hospital the next day.
On Tuesday, prosecutors revealed that they had received medical records mistakenly released by a hospital where the alleged victim was examined after the encounter, and passed those records on to Bryant's lawyers as part of the normal exchange of evidence.
Prosecutors subpoenaed the examination records from Valley View Hospital in Glenwood Springs. They not only received those, but were also given records from an earlier visit by the woman, prosecution spokeswoman Krista Flannigan said.
She declined to comment on the date or the nature of the earlier visit. "They were records they should not have given us," Flannigan said.
Hospital administrator Gary Brewer did not return calls.
Flannigan said the hospital requested the records be returned and copies destroyed, and that prosecutors complied. She didn't know if defense attorneys also complied.
The judge had earlier thrown out subpoenas issued by Bryant's attorneys for the woman's medical records. He said the trial judge should determine whether those records should be turned over if the case goes to trial.
Friends of the woman have said she tried to commit suicide in February and again in May.
Bryant, who is free on $25,000 bond, did not play when the Lakers went up against Phoenix Tuesday, although he did work out with the team, riding a stationary bicycle.