The beloved US actor was found dead at his California home on October 28, at the age of 54.

A police investigation into the death followed, which US authorities confirmed would continue in May after it was ruled an accident.

Perry had been getting ketamine infusion therapy for anxiety and depression at the time of the overdose, according to US media.

At least one of those arrested include a doctor, TMZ reports.

The arrests were made in Southern California on Thursday.

Law enforcement sources confirmed multiple agencies executed search warrants in an attempt to identify the supplier of the ketamine.

They reportedly seized phones as part of the raids, along with computers and other electronic equipment.

Perry was found “unresponsive in the pool at his residence” in Los Angeles on 28th October.

At the time, Los Angeles Police Department confirmed to the PA news agency that it is working with the Drug Enforcement Administration (DEA) on the “open investigation” into the circumstances of Perry’s death.

A medical examiner concluded the “overdose” followed the “acute effects of ketamine”.

It comes despite the therapist’s last known treatment coming one and a half weeks before his death.

This story is being updated.