In an interview with Access Hollywood, Judy Haim says an autopsy also found he had an enlarged heart along with the water in the lungs.
What role those factors played, if any, in Haim's death isn't known. L.A. Coroner Chief Craig Harvey confirms that the autopsy was completed at 11 a.m. Thursday, but notes, "There is no final cause of death at this time."
"The final cause of death has been deferred pending additional tests that have been ordered," he says.
Shortly before his death Wednesday at age 38, Haim complained of flu-like symptoms and had a high fever. His former fiancée, Tiffany Shepis, also tells PEOPLE the actor had long suffered from heart problems.
"Every time he would go to a doctor they'd tell him he had really bad arrhythmia, probably due to clogged arteries," she says. "They all said he should have it taken care of. But, being from Canada, his insurance was there, so he never went and got it done."
Shepis, who was engaged to Haim briefly between 2008 and 2009, says he also struggled with addiction. "His problem was with prescription drugs – painkillers and Valium," she says. "His addictions are common knowledge. And the longer [you] are addicted to something, the harder it is for you to quit. And that's what he was facing."
Additional reporting by KEN LEE and CHAMP CLARK