Michael Jackson (search) has reportedly given Santa Barbara County prosecutors a DNA sample.

Jackson is facing child molestation charges and authorities executed search warrants at his Neverland ranch on Friday and again Saturday, just weeks before the pop star is scheduled to go on trial for child molestation.

Authorities would not say why they returned to the storybook estate Friday, more than a year after dozens of investigators first raided it while they were still drawing up charges against Jackson.

But, the Santa Barbara News-Press reports that Jackson returned to his estate Saturday to give a DNA sample, obtained by placing a cotton swab in the pop star's mouth. What authorities planned to do with the sample isn't clear.

In a statement, the Santa Barbara County Sheriff's Department said only that the daylong search was "part of an ongoing criminal investigation." Spokesman Sgt. Chris Pappas said investigators entered Neverland at 9 a.m. and left about 8 1/2 hours later.

Jackson attorney Thomas Mesereau Jr. (search) had no comment.

Attorneys on both sides of the case are barred from commenting by a court gag order.

Jackson, 46, was charged in December 2003 with molesting a boy and plying him with alcohol. His trial is set to begin Jan. 31.

A new search so late in the proceedings is very unusual, said a former federal prosecutor who has been following the case.

"It may mean that the witnesses they are preparing for trial now are remembering things at the ranch that they did not mention before," said Laurie Levenson, a professor at Loyola Law School. "They may want to follow up on how certain things looked."

However, she said the search could also be connected to a dispute that has been going on between the prosecution and defense over the sharing of evidence. The defense has been resisting turning over material to the prosecution.

Levenson said if the search yields any physical evidence, it could be of dubious value. "At this stage, if they found anything, if I were Jackson's folks I'd say it was planted. So I'm not so convinced how valuable this would be," she said.

The late-stage search could also help the defense win a delay, Levenson said. "How do you go to trial in a case when they are still serving search warrants?" she said.

Jackson was home when authorities arrived Friday but left soon after because the presence of law enforcement officials was upsetting his children, sources close to the entertainer told the News-Press. He returned Saturday to provide the DNA sample, the newspaper said.

Neverland, set amid the emerald hills and horse ranches about 100 miles northwest of Los Angeles, was first searched in November 2003 by at least 60 investigators from the Sheriff's Department and district attorney's office.

The theme park-like estate has a mansion, zoo, bumper cars, a merry-go-round and Ferris wheel. Jackson hosted many children's parties there.

Monday is the deadline for prosecutors and defense lawyers to complete the case's discovery process in which both sides exchange evidence they have gathered during their pretrial investigations.

Jackson's trial is scheduled to begin at the end of January.

Fox News' Adam Housley and The Associated Press contributed to this report.