The late actor Corey Haim had a fraudulent prescription for a powerful painkiller that authorities said was obtained through a major drug ring.
A police spokesman said records of the prescription in the name of the former teen heartthrob were found during an investigation of the ring that illegally obtained prescription pads and used the stolen identities of doctors to fill them out.
"Corey Haim's death is yet another tragedy linked to the growing problem of prescription drug abuse," the spokesman said.
"This problem is increasingly linked to criminal organisations, like the illegal and massive prescription drug ring under investigation."
Los Angeles County coroner's officials, however, said they have not yet determined what killed 38-year-old Haim.
State law enforcement authorities said they were investigating the drug ring and how Haim, who battled addiction for years, obtained the prescription.
Assistant Chief Coroner Ed Winter said four prescription drug bottles bearing the actor's name were found in the apartment where he collapsed, but all those drugs had been provided by a doctor who had been treating the actor.