AceShowbiz - Police have closed their investigation into Matthew Perry's death. The former "Friends" actor's untimely passing was being looked into by authorities after he was found unresponsive in the hot tub of his Los Angeles home last October at the age of 54, but following the publication of his autopsy report, the Los Angeles Police Department confirmed to People magazine they are no longer dealing with the case.

In addition, the Los Angeles County Medical Examiner-Coroner have confirmed on their website that the case surrounding Matthew's death is considered "closed."

An autopsy result later found the "17 Again" actor's death was caused by acute effects of ketamine, while drowning, coronary artery disease and the effects of buprenorphine, a medication used to treat opioid abuse, were also listed as contributing factors.

Although Matthew's passing was listed as accidental, his former girlfriend, Kayti Edwards, called for there to be a bigger police investigation after the autopsy findings were published.

The actor, who was reportedly sober for 19 months before his death, had been receiving ketamine infusion therapy for depression but his final session was over a week before he died, meaning the drug in his system was not from his treatment.

Kayti told The U.S. Sun, "I'm pretty sure that in Matthew's brain ketamine infusions at a doctor's would count as still being sober. In his brain it's not the same as going on the street to buy crack or heroin. That probably was the stepping stone for him to go back to doing drugs. I wasn't surprised when the medical examiner's report dropped. I already knew what it was so it wasn't shocking to me."

"I wasn't there so I don't know exactly what happened but I do know Matthew as a person and a friend and I know the patterns that led up to this. I could see it from a mile away, he didn't seem right during the last couple weeks of his life. The sober people who knew him have never hung out with him when he was getting high so they wouldn't know the signs," she added.