Los Angeles (AFP) - A Los Angeles judge said on Tuesday he is mulling a mistrial in the civil rape case against National Basketball Association star Derrick Rose after lawyers for the plaintiff were accused of withholding key evidence.

Federal Judge Michael Fitzgerald said he was considering declaring the trial invalid because lawyers for Rose were not given access to several text messages they claim are essential to their case until the player was on the witness stand.

Fitzgerald described the situation as "careless" and ordered attorneys for Rose's accuser to prove the messages had been disclosed in good time before he makes a ruling on a motion filed by lawyers for the New York Knicks player.

Rose, Randall Hampton and Ryan Allen are being sued for at least US$21.5 million (S$29.66 million) in damages from a 30-year-old woman who claims she was gang-raped by the men at her apartment in Los Angeles in 2013.

The three men deny the allegations, claiming the sexual contact that took place was consensual.

Lawyers for the woman claim the text messages show the plaintiff was unaware the men were coming to her apartment and that she had no intention of having sex with them.

Rose's legal team say the texts prove the opposite - that the woman was a willing participant.

Rose, 28, gave further testimony on the witness stand on Tuesday, insisting that the plaintiff was "awake and alert" when he and his friends took turns having sex with her.

The basketball star said that after a party at his house, the woman had sent him a text message that read: "You need to come see me right now."

Rose said the woman greeted Rose and his two friends and told them they could have sex with her "one at a time".

The Knicks player said he believed the woman had "had a good night".

Lawyers for the plaintiff say their client was drugged by the men earlier in the evening and that she was unaware they had entered her apartment.

The case continues.