Matthew Perry's ketamine source becomes focus of investigation

The source of Matthew Perry's ketamine is part of an "open investigation" into the death of the actor in October, Los Angeles police confirmed Tuesday.

The Los Angeles Police Department said it is working with the Drug Enforcement Administration as part of a review of the case involving the "Friends" star, who was 54 when authorities say he died from the acute effects of ketamine. TMZ first reported that investigators were focusing on the source of the ketamine; the DEA declined further comment Tuesday.

Perry's unexpected death came after his very candid struggles with alcohol and opioid addiction and multiple stints in rehab. In 2022, he published a memoir, "Friends, Lovers and the Big Terrible Thing," in which he described an addiction to Vicodin after a 1997 jet-ski accident and how he nearly died in 2019 after his colon burst because of opioid abuse.

A Los Angeles County Medical Examiner’s Office report noted in December that the actor had reportedly been clean for 19 months before his death. His live-in assistant told police he was out running errands when he returned to Perry's Pacific Palisades home and found him unresponsive in the pool.

A coroner said Perry had reportedly utilized ketamine infusion therapy, which has grown increasingly popular to treat mental health issues, and had last done so 1½ weeks before his death. Perry used the anesthetic treatment for depression and anxiety, according to the report.

But the levels of ketamine still in his body were high — around what is used for general anesthesia during surgery — and the coroner said it was unclear why the drug would still be in his system since it metabolizes within hours.

The coroner ultimately ruled his death an accident, and said "contributing factors" included drowning, coronary artery disease and the effects of buprenorphine, which is "used to treat opioid use disorder."

On the day of his death, Perry's assistant said, the actor had been playing pickleball and had not complained about his health or showed evidence of alcohol or drug use. While there was no indication of foul play in the aftermath of his death, an investigation was ongoing, law enforcement had said.

It's not uncommon for law enforcement to investigate the source of a celebrity's drug-related death. Charges were filed against the person who supplied the counterfeit oxycodone drugs that led to the 2018 overdose death of rapper Mac Miller and against a drug dealer who supplied actor Michael K. Williams with the fentanyl-laced heroin that killed him in 2021.

The death of Perry, best known for playing the sarcastic Chandler Bing on "Friends," triggered an immediate outpouring of shock and grief among his former co-stars and fans.

This article was originally published on NBCNews.com