Jackson's Doctor Missing

Police are searching for Michael Jackson's personal physician, who cannot be found, to interview him after the singer's unexpected death Thursday afternoon.

TMZ.com has identified the missing physician as Dr. Conrad Robert Murray.

Some people are speculating whether Jackson's death was due to a prescription drug overdose.

A source close to the family told People magazine, that in 2006 Jackson's family grew worried about his taking prescription drugs and did an intervention in Las Vegas. A source close to the family said that Jackson had been taking straight morphine, Demerol, Oxycontin, Valium, and Xanax, and that he was an addict.

It will be unclear to determine the exact cause of Jackson's death until a toxicology test, which can take weeks, is completed, according to the New York Daily News.

The family's attorney, Brian Oxman, raised the question of Jackson dying from prescription drugs, perhaps was using them to get ready for his tour which was to begin next month, according to the New York Daily News.

Jackson's family said that the "King of Pop" was on Demerol, which can cause circulatory and breathing problems, as well as cardiac arrest.

The physician's car was impounded yesterday to see if there was anything inside—like prescription drugs—that may have contributed to Jackson's death. Law enforcement said that the doctor gave Jackson some kind of an injection before his death, according to TMZ.com.