LOS ANGELES, California (CNN) -- The Jackson family knows that the probe into singer Michael Jackson's death could turn into a criminal case, a source close to the family told CNN Thursday.
Los Angeles detectives are waiting on the coroner's report on the death of Michael Jackson.
"The family is aware of a potential criminal prosecution," the source, who did not want to be identified, said.
The comments came on the same day that Los Angeles Police Chief William Bratton said detectives were awaiting the coroner's report to decide whether to proceed with the investigation as a homicide or an accidental overdose.
Bratton said detectives have spoken to a number of doctors who have treated Jackson over the years and are looking into the singer's prescription drug history.
"We are still awaiting corroboration from the coroner's office as to cause of death. That is going to be very dependent on the toxicology reports that are due to come back," Bratton told CNN. "And based on those, we will have an idea of what it is we are dealing [with]: are we dealing with a homicide or are we dealing with accidental overdose?"
Doctors who did not cooperate with investigators were issued subpoenas, another source told CNN Thursday. If needed, authorities will issue more, the source said.
Bratton also said investigators are being assisted by agents from the Drug Enforcement Administration and the state attorney general's office on a case that he called "a comprehensive set of inquiries."
"At the time of the death with search warrants, we were able to seize a number of items from the residence where the death occurred and those will assist in the investigation," he said.
Bratton did not elaborate on what police found.
A source involved with the investigation told CNN earlier investigators found numerous bottles of prescription drugs in the singer's $100,000-a-month rented mansion in Holmby Hills. The Associated Press and The Los Angeles Times, citing unnamed sources, said police also found the powerful sedative Diprivan.
"We've got very good investigators. They will be prepared to deal with whatever the coroner's findings may be," Bratton said.
"He has his role and responsibility; we have our role and responsibility. The next move, really, is his."
CNN's Nancy Baker contributed to this report.
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