Actor Perry's death is being investigated because of the level of ketamine found in his blood

Matthew perry

Photo: Associated Press

An investigation has been opened into the death of Matthew Perry and how the actor of the series "Friends" took ketamine, which is considered a contributing factor in his death, reports the "AP" agency. 

Los Angeles Police Capt. Scot Williams said in an email Tuesday that the police department, in cooperation with relevant authorities, has begun investigating why the 54-year-old star had so much ketamine in his blood system when he died in October. The investigation was first reported in "TMZ" magazine.

Perry was found unresponsive in the hot tub of his Los Angeles home. His autopsy, released in December, found that there were amounts of ketamine in Perry's blood at the level used for general anesthesia during surgery. The drug is sometimes used to treat depression. 

The Los Angeles County Medical Examiner's Department said in an autopsy report that Perry drowned "at the bottom of the hot tub," but that it was a secondary factor in his death, which was ruled an accident. 

According to Perry's autopsy, people close to the actor told investigators he was undergoing ketamine infusion therapy, an experimental treatment used to treat depression and anxiety. But medical experts said his last treatment was a week and a half ago and that this could not explain the high level of ketamine in Perry's blood. The drug is usually metabolized in a few hours. 

Perry was among the biggest television stars of his generation when he starred in 10 seasons of the hit series Friends from 1994 to 2005. He starred alongside names like Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc and David Schwimmer.