Sheriff's investigators denied they are the source of recent leaks to the media in the Michael Jackson (search) child molestation case and added an investigation has been started to find who might be responsible.

A posting on the sheriff's Web site Monday said the information that has been released is covered by Superior Court Judge Rodney Melville's (search) sweeping gag order in the case.

"We consider the release of the these materials to be a violation of the law," the online statement said. "Some media commentators have alleged that we are responsible for these leaks. We are not. These accusations are irresponsible, unfounded and untrue."

Sgt. Chris Pappas (search) declined to comment further about the details, citing the judge's gag order.

The statement is, in part, a response to the recent ABC News report that quotes from transcripts of grand jury testimony given in the molestation case. Jackson's accuser described Jackson's alleged crimes in graphic detail, including an incident when the pop star allegedly molested him on a bed.

ABC has not revealed how it received more than 1,900 pages of grand jury testimony.

Grand jury transcripts normally are made public in California 10 days after a defendant receives them. The judge, however, has kept the Jackson transcripts sealed, along with most other documents in the case.

Jackson, 46, was indicted in April on multiple counts of molestation and a count of conspiracy involving child abduction, false imprisonment and extortion. He has pleaded not guilty and is scheduled to stand trial Jan. 31.

Also Monday, attorneys representing a group of media organizations filed a motion seeking to keep the testimony of child witnesses in the case open to the public.

Last week, prosecutors asked that testimony from Jackson's accuser and his brother be conducted in secret. They argued that the media and the public could listen to the testimony by an audio-only feed.

Attorney Theodore Boutrous argued in his motion Monday that the identities of the brothers were made public when they appeared in a documentary in February 2003 that was aired in the United Kingdom and the United States, and thus "there are no benefits created by eliminating the public's ability to observe the proceedings.

"The ability to observe, not merely to listen or read, testimony is a fundamental aspect of the public's First Amendment right to attend a criminal trial," Boutrous wrote in the brief.

Melville will consider the motion Friday.