Prosecutors in California have said they are looking into a possible link between the death of Canadian actor Corey Haim and an illegal trade in prescription drugs.

State Attorney General Jerry Brown's office said an unauthorised prescription under Mr Haim's name was found during an ongoing investigation of bogus prescription drug forms ordered from a San Diego supplier.

"Corey Haim's death is yet another tragedy linked to the growing problem of prescription-drug abuse," said the statement, issued two days after Mr Haim, 38, was found dead in Los Angeles last week after an apparent overdose.

"This problem is increasingly linked to criminal organisations, like the illegal and massive prescription-drug ring under investigation. It's a serious public health problem."

Coroners have yet to rule on the exact cause of Mr Haim's death, but the Toronto-born star of such 1980s films as Lucas and The Lost Boys was known to have had a long history of drug abuse that dented his career.

Dr Brown's office said the prescription drug ring under investigation specialised in ordering prescription forms from authorised suppliers using stolen doctors' identities.

The forms were then sold on the street to prescription drug abusers or to individuals who were paid to fill the prescription and then sell the drugs illegally, it said.