Kayti Edwards, who has urged police to widen their probe into the 54-year-old actor's death last October, said he once told her chillingly: "I'm in with the doctors."
Five people, including Matthew's live-in personal assistant and two medics, have been charged over his death at his Los Angeles home.
California Attorney Martin Estrada said the doctors "took advantage of Mr Perry's addiction issues to enrich themselves" by supplying him with a large amount of ketamine.
Jasveen Sangha, 41, who, according to prosecutors, was known as "the Ketamine Queen", Salvador Plasencia, known as "Dr P", and Erik Fleming, an acquaintance of Perry, are among those charged.
But Kayti, 47, said: "There's a whole network of people beyond those facing criminal charges who the police need to investigate.
"Detectives need only delve back into [Matthew's] medical history.
There are so many more doctors who have been on his books over the years who will be terrified right now.
"Whenever he was in active addition, he knew instantly where to turn. It's a scandal." Kayti, the stepgranddaughter of veteran British actress Julie Andrews, 88, dated Matthew in 2006 before becoming his assistant in 2011. They remained friends until his death.
She said: "Ketamine was his new thing, but it all started with unscrupulous doctors over-subscribing prescription pills like Vicodin.
"When the charges dropped, I knew they would be doctors.. because that was what he always did.
"His addictive brain would think 'Well, it was prescribed from a doctor so I can take it'. In his head, it wasn't like he was out on the street scoring drugs."
When she worked for him, Kayti was shocked by the sheer quantity of drugs Perry, who played Chandler Bing in the blockbuster US TV series, was consuming.
This story is from the August 24, 2024 edition of Daily Express.
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This story is from the August 24, 2024 edition of Daily Express.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
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