'Friends' star Matthew Perry died from "the acute effects of ketamine," according to a Los Angeles County Medical Examiner's Office toxicology report obtained by TMZ on Friday (December 15).

Last month, law enforcement sources told TMZ that less-in-depth tests were conducted on Perry, 54, which confirmed that he didn't die of a fentanyl or meth overdose. The sources acknowledged that more-in-depth tests to analyze whether other illegal drugs were present in his blood were still being conducted, which could take an estimated four to six months to be returned.

Perry was reportedly found underwater and not breathing in his hot tub by a person who called police on October 28, the Los Angeles Fire Department confirmed in a statement obtained by the New York Post on October 30.

“An adult male patient was deceased prior to first response arrival," the department said. “The patient was found by a bystander who had re-positioned the victim where the head was out of water.”

“Firefighters pulled the victim out of the jacuzzi and did a quick medical assessment to find he was deceased," the statement added.

The department didn't reveal the caller's identity, though TMZ reported it was Perry's assistant. Law enforcement sources told the website that the actor's body was not waterlogged when he authorities arrived at the scene.

Authorities said Perry's cause of death has been "deferred" and further investigation was requested as a toxicology report is pending, according to a report released by the Los Angeles Medical Examiner obtained by NBC News on October 29. The medical examiner's office added that the actor's body was ready to be released to his family, though toxicology results may not be available for several weeks.

A law enforcement source told TMZ that numerous prescription drugs were found inside Perry's Los Angeles home at the time of his death on October 28. Authorities reportedly found anti-depressants, anti-anxiety medication and a drug for Chronic Obstructive Pulmonary Disease, which is often prescribed to people dealing with emphysema or chronic bronchitis.

TMZ initially reported that no illegal drugs were found at the home of Perry who dealt with substance abuse during his life. Perry was best known for his iconic role as Chandler Bing, starring alongside Jennifer Aniston, Courteney Cox, Lisa Kudrow, Matt LeBlanc and David Schwimmer during all 10 seasons of 'Friends.'

Aniston, Cox, Kudrow, LeBlanc and Schwimmer issued a joint statement exclusively to PEOPLE on October 30, two days after Perry's death before later sharing individual tributes to their co-star.

"We are all so utterly devastated by the loss of Matthew. We were more than just cast mates. We are a family," the cast said in their joint statement. "There is so much to say, but right now we’re going to take a moment to grieve and process this unfathomable loss.

"In time we will say more, as and when we are able," the statement continues. "For now, our thoughts and our love are with Matty’s family, his friends, and everyone who loved him around the world."

All six actors achieved superstardom through their breakout roles on the show, which ran from 1994 to 2004.

"The best way that I can describe it is after the show was over, at a party or any kind of social gathering, if one of us bumped into each other, that was it. That was the end of the night. You just sat with the person all night long and that was it," Perry said when all six castmates appeared together during their 2021 reunion special via CBS News. "You apologized to the people you were with, but they had to understand you had met somebody special to you and you were going to talk to that person for the rest of the night," he continued. "And that's the way it worked."

Perry also starred in several later television series including 'Studio 60 on the Sunset Strip,' 'Go On' and the 2015-17 remake of 'The Odd Couple,' as well as film roles in 'The Whole Nine Yards,' 'The Whole Ten Yards' and 'Fools Rush In.'

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