Michael Jackson was "heavily addicted" to the powerful pain killer Oxycontin and received "daily doses" of it and of another pain killer, Demerol, according to a senior law enforcement official briefed on the initial investigation of his death.
The Los Angeles police were told Jackson received an injection of Demerol one hour before his death, the official said.
The information and other emerging details, make it almost certain the Los Angeles Police Homicide and Robbery Division will launch a full investigation into the circumstances of the pop singer's death. The squad was given the assignment initially because of the "high profile" nature of the case.
As part of the broadening investigation, police detectives are searching for Dr. Conrad Murray, a Las Vegas cardiologist, who was reportedly with Jackson yesterday but has not been located since.
A car towed by police from the Jackson home was registered in the name of Dr. Murray's sister, Susan Mary Rush of Houston, Texas.
"There is no immediate indication of a crime," a police official told ABC News, "but because of the high profile nature of the case the robbery and homicide detectives with review all evidence and work with the coroner's office."
The LAPD is also reportedly searching for a doctor who may be able to help in their investigation. Police say that they towed a BMW owned by the doctor from Jackson's home.
"We have not been able to interview the doctor yet. His car was impounded because it may contain medications or other evidence that may assist the coroner in determining the cause of death," said LAPD spokesperson Karen Rayner.
The Los Angeles coroner began an autopsy this morning although it could take several days before full results are known.
A Jackson family attorney, Brian Oxman, told ABC News today he had no hard evidence but that he feared Jackson died from "overmedications." On Good Morning America, Oxman said, "Drugs had been part of Jackson's life since the 1980's" and said he had warned family members that "if Jackson dies of overmedication I will not hold my tongue."
Federal agents said they also could become involve if there is evidence that a pharmaceutical drug played a role in his death, much as they did in the case of heiress Anna Nicole Smith who died of an accidental overdose of prescription drugs.
California attorney general Jerry Brown worked with the federal Drug Enforcement Administration in the Smith case and ultimately brought charges against her lawyer, Howard K. Stern, and a doctor. Brown said Smith and been drugged to the point of "stupefaction" and called Stern "a primary enabler."
There is a hearing scheduled for later this summer to determine whether prosecutors have enough evidence to proceed to trial. Both Stern and Smith's doctor have plead not guilty to the charges.