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Michael Jackson's defense team began its case Thursday, calling a celebrity witness who testified the pop star never touched him inappropriately despite earlier testimony that the two had showered together.

Wade Robson (search), a 22-year-old Australian and the first witness for the defense, said he has known Jackson since he was five years old. He testified he stayed at the Neverland ranch over 20 times, sleeping in Jackson's bedroom on all but three or four of those visits.

The two played video games, watched movies, talked and sometimes had pillow fights, but Robson said Jackson never touched him in a sexual way.

A former Jackson maid, the mother of a boy who got a multimillion-dollar settlement from Jackson in the 1990s after accusing the star of molestation, testified previously that she once saw Jackson showering with Robson. Robson denied ever taking a shower with Jackson.

In cross-examination, prosecutor Ron Zonen (search) suggested it was possible Jackson had molested Robson when he was asleep.

Robson responded, "I would think something like that would wake me up."

Zonen then sought to suggest that Robson was so tired from dance practice and having fun at Neverland that he might have slept heavily.

Under further cross-examination, Robson acknowledged that Jackson helped him move from Australia to the United States in September 1991 and that he was grateful for the help.

Robson, a choreographer who has worked with Britney Spears and hosts his own show, "The Wade Robson Project," on MTV, was once in a music video with Jackson.

The testimony came as news surfaced that one of the jurors is in jeopardy of being kicked off the panel because of ties to Jackson, who is on trial for charges that he molested a boy at the Neverland Ranch.

Earlier Thursday, the judge denied a defense motion for an acquittal after the pop star's attorneys said the prosecution witnesses had "a tendency to self-destruct" on the stand.

Superior Court Judge Rodney S. Melville (search) immediately called in the jury to begin hearing the defense case.

Defense motions for acquittal are common when the prosecution rests, but are rarely successful.

The prosecution rested Wednesday after calling more than 80 witnesses in an attempt to prove Jackson fondled a 13-year-old cancer survivor, plied him with alcohol, and conspired to detain him and his family so they would rebut a damaging documentary by Martin Bashir in which Jackson said he let children sleep in his bed.

Robson and a defense witness who testified later Thursday, Brett Barnes (search), were among individuals mentioned in the portion of the prosecution case intended to show that Jackson has a pattern of past inappropriate behavior with boys.

Barnes, 23, of Melbourne, Australia, said he met Jackson at age 5 when the singer passed through Australia on tour. He said he was already a Jackson fan and his mother wrote a letter telling Jackson about him.

"After a while, we received a phone call from him and we became really good friends," he said.

Barnes said that as a youth he stayed with Jackson at least 10 times. Asked if he had ever been touched inappropriately, Barnes said, "Never, I wouldn't stand for it."

In response to witnesses' prior testimony that he had been touched inappropriately by Jackson, Barnes denied said, "I'm very mad about it. It's not true and they put my name through the dirt. I'm really not happy about it."

While cross-examining Robson, Zonen approached the witness stand carrying two books taken from Jackson's home, one showing nude boys and the other showing men in sexual acts.

Robson said he did not consider the book about boys to be pornographic, but he appeared to be taken aback when shown the book depicting men in sex acts.

"Would you be concerned with a man who possesses that book crawling into bed with a 10-year-old boy?" Zonen asked.

Robson paused and said quietly, "Yes."

Defense attorney Thomas Mesereau Jr. (search) quickly countered, asking Robson if he would feel differently if he knew that Jackson also had a collection of 10 years' worth of Playboy, Hustler and other heterosexual pornographic magazines.

Robson said he would feel differently and would no longer be concerned about it. He also said Jackson had never shown him sexually explicit material.

Mesereau also pointed out Robson's fiancee in the courtroom and had him confirm that he is heterosexual.

As part of their effort to convince the judge to acquit Jackson, the singer's attorneys said the accuser, his brother and his mother told a string of lies on the stand, calling the mother a "bizarre" witness who told a "whopper."

"This is one of the most clearly deceptive witnesses that has ever appeared in any court," defense attorney Robert Sanger (search) said.

He said the mother was clearly dishonest when she said that her video interview rebutting the documentary was false. He also said the accuser's brother falsely said he never pulled a knife on a woman, and the sister gave false accounts of where she slept at Neverland.

Sanger also said witnesses such as flight attendant Cynthia Bell, former Jackson employee Jesus Salas and Jackson's ex-wife Deborah Rowe were called by the prosecution but gave testimony favorable to Jackson.

District Attorney Tom Sneddon (search), who has pursued Jackson for more than a decade, countered that the evidence against the pop star was overwhelming.

"The motive of Michael Jackson is clear," he said. "The evidence is overwhelming. This was a death threat to his career. He was hemorrhaging financially. He had a cash-flow problem. The Bashir film was the last stroke that was going to end his career if something wasn't done."

The judge said he was reluctant to make a decision about the credibility of the witnesses, suggesting that was the jury's job.

Melville also heard arguments but did not immediately rule on whether some items presented during the prosecution case had been sufficiently authenticated by testimony to be admitted into evidence.

The Associated Press and FOX News' Trace Gallagher contributed to this report.