Charlie Sheen investigated by police for threatening his dentist with a knife

Los Angeles - Charlie Sheen is being investigated for allegedly threatening his dentist with a knife.

The Anger Management actor is under investigation for assault with a deadly weapon following the incident in Los Angeles last Thursday when he sought treatment for an abscess and reportedly went "insane" when a technician placed a mask over his face to administer nitrous oxide.

According to TMZ, the technician told police the 49-year-old star was flailing his arms and striking her, so she left the room as the actor's security guard entered.

Following a "lot of commotion", Charlie's dentist - who had also been in the room along with an oral surgeon - left the room and told the technician his famous patent had gone after him with a knife, but he was unhurt.

The technician also reported to officers that Charlie's bodyguard had told the dentist the former Two and a Half Men star was "high on rock cocaine".

Police are investigating the claims and Charlie could face charges of possible battery against the technician and felony assault with a deadly weapon for the alleged knife attack on the dentist.

Officers are keen to interview both the actor and the dentist before sending the case to the district attorney's office, who will decide whether or not to prosecute.