Actor Corey Haim shown on March 19, 2009, in Hollywood, died on Wednesday. His cause of death hasn't been confirmed. (Michael Buckner/Getty Images)

Actor Corey Haim had a fraudulent prescription when he died that was linked to a major drug ring, authorities say.

The California Attorney General's Office said Friday it was investigating the drug ring and how the Toronto-born actor obtained the prescription.

Haim, a 1980s heartthrob who starred in The Lost Boys and License to Drive, died Wednesday at age 38.

An autopsy was performed on Thursday, but the coroner's office has not declared a cause of death. Toxicology tests could take another six to eight weeks.

However, Haim's mother, who was with him in Burbank, Calif., at the time of his death, said the coroner's office told her Haim had an enlarged heart and water in his lungs. She said she was told the cause of death may be pulmonary congestion.

Haim had complained of flu-like symptoms in the days before his death. He had battled drug addiction for years.

Winter declined to say what prescription drugs had been found in Haim's apartment.

Manager says burial in Toronto: magazine

Born in Toronto in 1971, Haim was enrolled in acting classes by his mother as a way for him to get over his shyness.

His first professional job was in the 1984 movie Firstborn. He also had a continuing role in the CBC-TV series The Edison Twins, which ran from 1982 to 1986.

He shot to stardom with the 1986 film Lucas, but his career hit the skids in the 1990s.

More recently, he starred in the reality series The Two Coreys with Corey Feldman from 2007 to 2008, and had completed several film projects.

His manager, Marc Haislip, told Us magazine that Haim will be buried in Toronto. There is no word on the date.

With files from The Canadian Press