MICHAEL JACKSON was last night urged to turn himself in as officials in the US revealed he faces multiple counts of child molestation.

An arrest warrant has been issued for the pop superstar amid reports that a 12 or 13-year-old boy has made an allegation of sexual abuse against the singer.

Jim Anderson, sheriff of Santa Barbara County, in California, said bail had been set for the celebrity at $3m (£1.7m) and said: "We encourage him to turn himself in."

Sheriff Anderson told a Press conference that 70 investigators from the Santa Barbara County Sheriff's Department and Santa Barbara District Attorney's office served a search warrant at the star's Neverland ranch and spent all Tuesday searching the site.

He said that at the same time two search warrants were served in southern California.

He said: "The service of the warrants was part of an ongoing investigation alleging criminal misconduct on the part of Michael Jackson. The basis for this investigation regarding Michael Jackson involves allegations of child molestation.

"Mr Jackson has been given an opportunity to surrender to the custody of the Santa Barbara Sheriff's Department within a specified period of time.

"We are currently working with Mr Jackson's legal representation on this matter. Mr Jackson has also been directed to surrender his passport when he's taken into custody."

Jackson's friend, illusionist Uri Geller, urged the star to "grow up".

He said: "This is definitely shocking.

"Whatever the outcome of this case this must force Michael Jackson to grow up.

"The name of his latest single is One More Chance. I fear Michael Jackson has used his last chance."

In 1993, a 14-year-old boy accused the singer of molesting him. The former Jackson Five star maintained his innocence and agreed an out-of-court settlement, but he has been dogged by controversy ever since.

And he caused more controversy when he admitted to sleeping in the same room as children at Neverland.

Santa Barbara County District Attorney Tom Sneddon said there were a number of factors that made this investigation different from the alleged incident in 1993.

He said the law in California had been changed because of the case involving the singer.

In 1993, a child victim could not be forced to give evidence in a molestation case, but "as a result of the Michael Jackson case the legislator changed that law, and that is no longer the law in California", he said.

Mr Sneddon said the current case was different because the officials had a "co-operative victim in these particular proceedings".

In a statement, Jackson has denounced media coverage of the search of his ranch.

He said: "I've seen lawyers who don't represent me and spokespeople who do not know me speaking for me. They always seem to surface with allegations just as another project - an album, a video - is being released."

Mr Sneddon said that any musical projects Jackson might be involved with had no bearing whatsoever on the investigation.

He said: "It's being suggested that this is to do with the release of Jackson's CD - as if the sheriff and I are into that kinda music."