Los Angeles police confirmed Wednesday that actor Charlie Sheen is the subject of a criminal investigation.

Variety said that while an LAPD representative also confirmed a search warrant had been obtained, the rep could not state the nature of the investigation or the alleged victim. That trade magazine as well as The Hollywood Reporter both noted that according to tabloid reports, an audio recording appears to contain Sheen, 50, ranting that he would pay someone $20,000 to kill or harm former fiancee Scottine Ross, known professionally as adult-film star Brett Rossi.

In early December, Ross, 26, filed a lawsuit against the “Anger Management” and “Two and a Half Men” star claiming he did not disclose to her his HIV status, with which he had gone public the month before. “As a result of this exposure, she has suffered serious emotional distress from a reasonable fear that she will contract HIV,” states the suit, which also alleges assault and battery.

Variety said it had received no immediate response from Marty Singer, an attorney for Sheen, whom the magazine contacted for comment.