NEW YORK • Celebrity website RadarOnline.com and the National Enquirer tabloid on Thursday refused to hand over material sought by the authorities investigating threats that those media reported actor Charlie Sheen had made against a former girlfriend.

The latest commotion involving Sheen, which began as celebrity gossip, appears to have become a battle over press freedom and a possible criminal case.

The thrice-married Sheen's career has been overshadowed for years by his admittedly raucous lifestyle, substance abuse, stints in rehabilitation and fondness for dating porn stars.

Los Angeles police on Tuesday served a search warrant on the New York headquarters of American Media, the parent company of RadarOnline and the National Enquirer.

The LAPD said its threat management division had opened a criminal investigation into Sheen.

The probe follows reports by RadarOnline and the National Enquirer about audio in which a man, said to be Sheen, is heard saying he would like to see a former fiancee "have her head kicked in".

The two media outlets said the warrant is illegal.

The publications first reported on the audio at the end of March, saying it was provided by a former lover of Sheen. They have reported quotes from the audio, but have not made it available online.

According to a copy provided on Thursday by RadarOnline of the search warrant and an affidavit, the police investigation was triggered by Scottine Ross, a former porn star and fiancee of Sheen's, who accused him in a December lawsuit of assault and of having sex with her without revealing he was HIV positive.

Sheen said last November he had been diagnosed with HIV about four years earlier, but said it was"impossible" that he had transmitted the virus to anyone else.

According to the affidavit, Ross went to police fearing for her life after reading the initial RadarOnline and National Enquirer reports in March, which said that Sheen had made threats against Ross in calls to another unidentified woman.

REUTERS