Matthew Perry’s live-in assistant, two doctors and a woman dubbed “the ketamine queen” are among five people charged following an investigation into the actor’s death.

The investigation unearthed a “broad underground criminal network” of people who “took advantage” of the Friends star after he fell back into addiction in autumn last year, US attorney Martin Estrada told a press briefing in Los Angeles.

The briefing heard Perry had been seeking treatment for depression and anxiety when he became addicted to intravenous ketamine, turning to “unscrupulous doctors who saw Perry as a way to make quick money”.

According to the indictment, Salvador Plasencia is said to have conspired with fellow doctor Mark Chavez to supply the actor with large amounts of ketamine, writing in a message: “I wonder how much this moron will pay” and “let’s find out”.

Plasencia allegedly used Perry’s live-in assistant Kenneth Iwamasa to distribute approximately 20 vials of ketamine to the actor over a two-month period from September to October 2023 “in exchange for 55,000 dollars” (£43,000).

Perry, who played Chandler Bing in hit US sitcom Friends, died aged 54 from the “acute effects of ketamine” on October 28 last year – after receiving several injections from Iwamasa.

Iwamasa, 59, of Toluca Lake, pleaded guilty on August 7 to conspiring to distribute ketamine causing death – admitting to “repeatedly injecting Perry with ketamine without medical training”.

Plasencia, who is charged with conspiracy to distribute ketamine, seven counts of distribution of ketamine and two charges related to allegations he falsified documents during the investigation into Perry’s death, pleaded not guilty during a court appearance.

His lawyer Stefan Sacks asked the judge if the doctor would be allowed to continue to operate the clinic he owns, given he had already surrendered his Drug Enforcement Administration (DEA) licence to prescribe controlled substances.

Prosecutor Ian Yanniello claimed it would be “inappropriate” given Plasencia had “essentially acted as a street corner drug dealer”, Mr Sacks arguing the case was “unique”.

Magistrate Judge Alka Sagar ruled a notice must be placed at the doctor’s clinic and patients must sign a form consenting to receiving medical treatment given the charges against him.

The judge set the next court appearance as October 8 before wishing Plasencia “good luck”, to which he responded: “Thank you so much, I appreciate that.”

Plasencia can be released after posting a 100,000 dollar (£78,000) bond.

The judge denied bond for Jasveen Sangha – an alleged drug dealer named by authorities as “the ketamine queen”.

Mr Estrada said Sangha allegedly sold approximately 50 vials of ketamine to Perry for 11,000 dollars (£8,553) in cash.

During the last few weeks of his life, Perry “turned to street dealer” Erik Fleming who is said to have sourced ketamine from 41-year-old Ms Sangha, of North Hollywood.

Fleming, 54, of Hawthorne, pleaded guilty on August 8 to conspiracy to distribute ketamine and distribution of ketamine resulting in death.

“The ketamine supplied by Sangha would ultimately be the dose that took Matthew Perry’s life,” DEA administrator Anne Milgram told the briefing.

Sangha pleaded not guilty to conspiracy to distribute ketamine, maintaining a drug-involved premises, possession with intent to distribute methamphetamine, possession with intent to distribute ketamine and five counts of distribution of ketamine.

The judge ruled she should remain in custody, noting the prosecutor’s concerns over destroying evidence and her dual citizenship which could provide an opportunity to flee.

Sangha is set to appear in court on October 15.

Mr Estrada said Plasencia is facing a maximum sentence of 120 years in federal prison, while Sangha is facing life imprisonment.

The office for the US Attorney also confirmed that San Diego physician Chavez, 54, has agreed to plead guilty to conspiracy to distribute ketamine, admitting he sold the drug to Plasencia having obtained it fraudulently.

During a press briefing, Ms Milgram said Chavez charged Perry 2,000 dollars (£1,500) for a vial that cost him approximately 12 dollars (£9).

Ketamine is a sedative that can be used as a recreational drug, as well as to treat depression and pain management.

A medical examiner said Perry had been receiving ketamine infusion therapy for depression and anxiety with his last-known treatment one-and-a-half weeks prior to his death.

“The ketamine in his system at death could not be from that infusion therapy,” the report said.

Perry was open about his battle with substance abuse and addiction, setting up a sober living facility for men with similar issues.

Following his death, a foundation was set up in his name to help those struggling with addiction.