Former child star Macaulay Culkin (search) took the witness stand Wednesday to testify for the defense in Michael Jackson's (search) child molestation trial, blasting allegations that he was once molested by the pop star as "ridiculous."

Jackson attorney Thomas Mesereau Jr. asked Culkin, now 24, what he thought of the charges against Jackson.

"I think they're absolutely ridiculous," said Culkin, who testified for 90 minutes before leaving the stand and exiting the courtroom.

He said prosecutors never approached him about whether Jackson had ever molested him, and that he only learned of the allegations that he had been sexually abused by watching news coverage of the trial.

"Somebody told me you should probably check out CNN because they're saying something about you," Culkin said. "I just couldn't believe it. ... It was amazing to me that nobody even approached me and asked if these allegations were true."

Culkin, the godfather of two of Jackson's three children, testified that he and Jackson were drawn together by their common experience as child performers, although he laughingly noted that "it was not like a child actors' self-help group."

"We're a part of a unique group of people. ... He'd been through that before, so he understood what it was like to be put in that position I was in, to be thrust into it," Culkin said.

"Anyone who was a child performer," he said, "we keep an eye out for each other."

Prosecution witnesses testified earlier that Jackson inappropriately touched Culkin, who was a frequent childhood guest of Jackson's. That testimony was used to allege that Jackson has a pattern of inappropriate behavior with boys.

Those witnesses included a chef who testified he saw Jackson with his hand up Culkin's shorts as the singer held the boy up to a video game at Jackson's Neverland ranch.

A former maid also testified previously that Culkin stayed in Jackson's bedroom during visits to Neverland. That woman, whose son received a $2.4 million settlement from Jackson in 1994, was attacked by the defense because she was paid $20,000 to appear on a TV show.

Culkin admitted he'd slept in Jackson's bed occasionally, but said he usually wore a T-shirt and socks and never engaged in anything inappropriate with Jackson.

The star of the "Home Alone" movies said he began visiting Neverland when he was 10 years old, and has remained friends with the singer ever since.

He said he took trips and played video games with Jackson and received gifts from him, but testified that the relationship was never anything except a platonic friendship and the two always had fun together.

Prosecutors asked Culkin whether he was sure Jackson never molested him when he was asleep.

"I think I'd realize something like that," Culkin said.

He laughed off many of the prosecution's questions and implications that he and Jackson had had a sexual relationship, saying that he and Jackson were very good friends and that the pop singer had always been generous with him.

He said his family has been to Neverland several times and has been in the singer's bedroom. He said he never felt his family was excluded from the bedroom or any other part of the ranch.

Culkin was also asked about whether he had ever seen anything improper happen with Brett Barnes or Wade Robson, the two young men who also testified for the defense last week.

"I've never seen him do anything improper with anyone," Culkin said.

Culkin is the third young man to appear for the defense to deny he was a victim of improper behavior by Jackson during childhood visits.

Culkin testified that he slept in Jackson's bed several times between the ages of 10 and 14, sometimes with other boys as well. He said the sleepovers weren't planned and that he and other guests would just fall asleep when they were tired.

Prosecutors seized on Culkin's description of Jackson as childlike and his account of how guests in Jackson's room were free to look at memorabilia.

The prosecution has shown the jury dozens of sexually explicit magazines found in Jackson's room during a November 2003 search, and have alleged that the pop star showed the material to his accuser and the boy's brother.

Asked if he thought it was childlike to have such material, Culkin said, "When I was 12 or 13 years old I had a couple of Playboys under my bed."

Culkin said he learned of the 1993 allegations because Jackson called and told him. He said Jackson told him he needed him to be a friend and Culkin agreed.

On cross-examination, Senior Deputy District Attorney Ron Zonen asked Culkin if prosecutors had tried repeatedly to contact him but had been rebuffed.

"Not that I know of, no," Culkin said.

Zonen asked whether prosecutors had attempted to contact him in 1993 — during an investigation involving another boy — and then again recently, when his attorney said he wouldn't give statement to either side prior to his testimony.

Culkin said his lawyer had suggested he not talk to attorneys in advance, and he agreed.

"I wasn't really planning on testifying," he said.

The actor entered court through a back entrance and was not seen by photographers or about two dozen Jackson fans outside the courthouse.

Courtroom observers said Culkin was calm and convincing on the stand. He wore a suit with an open-neck shirt and answered questions directly during his nearly 90 minutes of testimony.

Culkin has had his own legal problems recently. He was arrested Sept. 17 in Oklahoma after police stopped a car in which he was a passenger. Officers found some marijuana and several tablets of a medication used to treat depression and panic disorders, court records say.

Culkin has pleaded innocent to the charges and is free on $4,000 bail. Another hearing in that case was set for next month.

Jackson is accused of molesting a 13-year-old boy in 2003, giving him wine and conspiring to hold the boy's family captive to get them to rebut a TV documentary in which the boy appeared with Jackson, who said he let children sleep in his bed but that it was non-sexual.

FOX News' Roger Friedman, Catherine Donaldson-Evans and The Associated Press contributed to this report.