Matthew Perry's cause of death is expected to be explained by an "unknown drug", a former medical examiner has claimed. The Friends star tragically died at the age of 54 on October 28, after he was found unresponsive in a hot tub at his home in California. His death certificate was released on Tuesday, 14 November, with the actor's cause of death listed as "pending investigation" as the medical examiner's office awaits toxicology and lab results.