Los Angeles, California (CNN) -- Although Corey Haim's heart was enlarged and he had fluid in his lungs, the coroner's chief investigator says a drug overdose has not been ruled out as the cause of the actor's death.
Haim got two powerful drugs from a pharmacy just 11 days before his death, according to a source with knowledge of the transaction.
His primary care doctor did not know about the prescriptions and called the pharmacy two days later to find out what Haim had been given, the source said.
Haim's manager and a close friend told CNN that Haim began seeing an addiction specialist just two weeks before his death.
The 1980s teen movie actor, who struggled for decades with drug addiction, died early Wednesday after collapsing in the Los Angeles apartment he shared with his mother, authorities said.
"You can have somebody with an enlarged heart and some other medical conditions, but you don't know if the actual cause of death is from illegal substances, medication or heart failure," Los Angeles County Deputy Coroner Ed Winter told CNN on Friday.
Haim's manager, Mark Heaslip, said the coroner's office called Haim's mother Thursday with word that the autopsy revealed the enlarged heart and that pulmonary congestion was believed to have killed him.
Heaslip said this was evidence that Haim's death was not caused by a drug overdose, but Winter disputed that in a CNN interview Friday.
"There were some preliminary findings, and we agreed to let the mother know what those were," Winter said. "It was explained to her that even though this is some preliminary findings that the doctor observed, there wouldn't be a final cause of death until the final toxicology tests are back."
The cause of death may not be determined for another six weeks, Winter said.
Several prescription drug bottles were taken from Haim's apartment, he said. Although the bottles indicated the drugs included Vicodin, Valium and Soma, no tests have been done to confirm what they are, he said.
Haim had a prescription for the muscle relaxer Soma and the narcotic pain reliever Norco filled at a pharmacy February 26, a source with knowledge of the transaction said.
Two days after Haim personally picked up the drugs, his primary care doctor called the San Fernando Valley pharmacy to ask about the prescriptions, the source said.
The doctor said that "Haim was not feeling well" and that he needed to know what drugs had been prescribed for the actor, the source said.
The source, who worked at the pharmacy, asked not to be identified because his employer had not authorized him to talk.
Tiffany Shepis, who was engaged to be married to Haim a year ago, said on HLN's "Issues With Jane Velez-Mitchell" that he was taking large amounts of Valium and Vicodin during their yearlong relationship.
"You're talking about a person that, at the time when I knew him, you know, was ingesting 40 some-odd pills a day," Shepis said.
Longtime friend and frequent co-star Corey Feldman asked Wednesday that people not "jump the gun" to conclude a drug overdose killed Haim.
Heaslip, manager to both Feldman and Haim, said Haim had seemed to be winning his battle against drug abuse in the weeks before his death.
Haim was "weaned down to literally zero medications" in the two weeks before his death by an addiction specialist, Heaslip said on "Issues With Jane Velez-Mitchell" on Wednesday.
The doctor "put him on a new line of medications," Feldman said on CNN's "Larry King Live" on Wednesday.
Haim's death came as his career was picking up; he was booking "movie after movie," Heaslip said. His latest film is set for release soon, he said.
Haim "really became a man" in recent months as he helped his mother in her battle with cancer, Feldman said. "He's been there for her, taking care of her, being responsible."
Feldman said he was angry about how the entertainment industry had snubbed Haim in recent years. He was broke, without a car and living in a month-to-month rental apartment with his mother, he said.
"We build people up as children, we put them on pedestals, and then, when we decide that they are not marketable anymore, we walk away from them," he said.
Haim's most famous role was in the 1987 movie "The Lost Boys," in which he appeared with Feldman. Haim played a fresh-faced teenager whose brother becomes a vampire.
In later years, the two friends -- who appeared in eight movies together -- struggled with drug abuse and went their separate ways. They reunited for a reality show, "The Two Coreys," in 2007, but A&E Network canceled the program after slightly more than a year.
In a 2007 interview on CNN's "Larry King Live," Haim and Feldman discussed their battles with drugs. Feldman told King that he had gotten clean, but it took Haim longer.
Haim called himself "a chronic relapser for the rest of my life."
"I think I have an addiction to pretty much everything," he said. "I mean, I have to be very careful with myself as far as that goes, which is why I have a support group around me consistently."
In 2008, Feldman told People magazine that he would not speak to Haim until his former co-star got sober. In a clip from "The Two Coreys," Feldman and his wife, along with two other former teen stars, called on Haim to get him to admit he needed help, the magazine said.
The meeting followed an incident in which Haim, scheduled to film a cameo appearance in a direct-to-DVD sequel to "The Lost Boys," appeared on the set "clearly under the influence," People reported.
Feldman told King on Wednesday that he renewed his contact with Haim in the past year because of the progress he had made against his addiction.
Haim was born December 23, 1971, in Toronto, Ontario, according to a biography on his Web site. He made his first television appearance in 1982 on the Canadian series "The Edison Twins." His first film role was in the 1984 American movie "First Born."
Haim also won rave reviews for his title role in the 1986 film "Lucas." Film critic Roger Ebert said of him at the time, "If he continues to act this well, he will never become a half-forgotten child star, but will continue to grow into an important actor."
Following "The Lost Boys," Haim and Feldman appeared in "License to Drive" and "Dream a Little Dream."
CNN's Brittany Kaplan and Jack Hannah contributed to this report.