LOS ANGELES - Chris Rock testified at a private eye's racketeering trial Friday that he hired the man to investigate a model who demanded money after claiming she was pregnant with his baby, and who later accused him of sexual assault.

Outlandish and animated on stage, the 43-year-old comedian looked uncomfortable and spoke in hushed tones as attorneys asked him about his connection to Anthony Pellicano.

Pellicano and four other co-defendants have pleaded not guilty to using wiretaps and other tactics to dig up dirt to help clients in legal and other disputes. Rock was the latest star to testify at the trial; other celebrity witnesses included Garry Shandling, Keith Carradine and Paramount studio head Brad Grey.

Dressed in a black designer suit, Rock told jurors during his 15-minute appearance on the witness stand that he first hired Pellicano in 1999 through his attorney but did not know about his tactics.

Rock said he was the target of a shakedown by the woman who claimed she became pregnant during a one-night stand at the Beverly Hills Hotel while Rock was separated from his wife.

"Someone who was not pregnant with my child claimed to be pregnant with my child and requested large sums of money," Rock testified.

He testified that DNA tests showed he was not the father of the child.

Prosecutors have said the woman's name was illegally run through a criminal database in July 1999 by former Los Angeles police Sgt. Mark Arneson, a co-defendant in the case.

Rock testified that he hired Pellicano again two years later after the woman claimed the comedian had sexually assaulted her.

Prosecutors played a one-minute snippet from a 2001 audio recording between Rock and Pellicano in which the detective tells him he had a copy of a police report filed by the woman.

"I don't want to embarrass you," Pellicano said on the tape. "I'm going to read this to you. I'm not supposed to have this thing, you understand?"

Rock testified that he never actually saw the police report. He was never arrested or charged in connection with the sexual assault allegation.

"I'm here as a free man," Rock testified. "You know, I didn't do anything wrong."

On cross-examination, Arneson's attorney Chad Hummel asked if Rock knew what kind of information Pellicano was getting for him.

"I relied on what my lawyer told me," Rock said.

Rock also said he didn't know Pellicano was following the woman around town.

Prosecutors allege Pellicano, who is acting as his own lawyer, led a criminal enterprise by bribing police officers and telephone workers to get information.

Sylvester Stallone and former Hollywood superagent Michael Ovitz are among those on the prosecution's witness list, though they haven't been called to testify and it was unclear if they would take the stand.

Rock entered the courtroom with his hands crossed behind his back. Some jurors shifted in their seats to get a better look at the one-time "Saturday Night Live" player.

Rock answered most of the questions by simply saying "yes" or "no." He grimaced a few times and rubbed his eyes and head.

Rock's discomfort was obvious from the moment he was sworn in by a court clerk. Asked to say and spell his name, Rock meekly complied.

U.S. District Judge Dale Fischer asked the actor to speak up and say his name again.

"Mr. Rock, project," Fischer said.

Source: AP