A former medical examiner has said that Matthew Perry may have died from an unknown drug.
Matthew Perry, who was 54, died at his home in Los Angeles on October 28. His body was found unresponsive in a hot tub.
He was laid to rest at Forest Lawn Memorial Park cemetery on November 3.
The official cause of death has not yet been determined, but it is not being treated as suspicious.
Full toxicology results will take a few more weeks to return, but an initial investigation found no fentanyl or methamphetamines in Perry's system.
However, this week, former chief medical examiner Dr Michael Baden said that Perry may have died from an unknown drug.
Dr Baden told Fox News Digital, "They've got pretty much 99% of what they're going to get at this point as far as information goes, and they can release it now, or they can wait for a couple more weeks because they're looking for some unknown drug."
He added, "They might be doing microscopic slides, but it's now about almost two weeks, so the toxicology should be finished."
Perry's death certificate was obtained earlier this month by E! News. The informant on the certificate was Perry's stepfather.
The certificate also confirmed that the actor was found dead at his home in the Pacific Palisades outside of Los Angeles.
There were no other significant conditions contributing to Matthew Perry's death, according to the death certificate.
The death certificate also revealed that the deceased actor was buried at Forest Lawn Memorial Park cemetery.
Emergency responders were called to Perry's home for a "water rescue situation," but he was found dead on the scene. Authorities are still investigating the details of his death.
Since Perry's death, fans and co-stars alike have expressed their sorrow through touching tributes.