Friends actor Matthew Perry was experiencing an out-of-control ketamine addiction, injecting the drug six to eight times a day, before his accidental overdose death, prosecutors say. Five people have been charged in connection with Perry’s death, including his personal assistant, Kenneth Iwamasa, and one of those accused of providing the drug, Dr Salvador Plasencia. In court documents filed Thursday, federal prosecutors accuse Plasencia of telling a patient that Perry was “too far gone and spiralling in his addiction” the week before he died but that he still offered to sell Perry ketamine through Iwamasa anyway.

Know the news with the 7NEWS app: Download today Perry had been undergoing ketamine infusion therapy to treat depression and anxiety, but it was not the supervised therapy doses that killed him. His last session was more than a week before his death. According to prosecutors, Perry had been seeking out unsupervised doses of the controlled substance and had developed an “out of control” dependence on it.

Ketamine, an anaesthetic with psychedelic properties, is a popular party drug that has recently been found to be a promising alternative treatment for some mental illnesses but carries serious medical risks. Perry, 54, was found face down in the heated end of a pool at his Pacific Palisades home on October 28. When he died, the levels of ketamine in his body were high — equivalent to the amount used for general anaesthesia during surgery, according to the .