Canadian actor Corey Haim died of pulmonary congestion, the Los Angeles county coroner's office announced on Thursday.
The office told the mother of the 38-year-old that the death of the one-time teen idol had nothing to do with drug overdose as previously been suspected.
Haim collapsed in bathroom on Wednesday and was rushed to hospital in Los Angeles where he was later pronounced dead.
The coroner's office is still waiting for the toxicology results of four bottles of prescribed medicines found in the bathroom before it can decide what actually killed the Canadian actor.
Haim, a 1980s teen heartthrob, starred in movies such as "Firstborn", "Lucas", "Murphy's Romance", "The Lost Boys", "License to Drive", and "Dream a Little Dream".
Haim also co-starred in a TV reality show "The Two Coreys".
He was attempting a return to movie and stage acting and had at least nine projects in various phases of production at the time of his death.
Haim had been living with his mother in Los Angeles to help her fight breast cancer.