Dr. Conrad Murray was hired by AEG Live to accompany the pop star to London for his comeback series of concerts, said AEG Live President and Chief Executive Randy Phillips.
"As a company, we would have preferred not having a physician on staff full-time because it would have been cheaper without the hotels and travel, but Michael was insistent that he be hired," Phillips told The Associated Press. "Michael said he had a rapport with him."
Jackson, who collapsed Thursday at his rented home in Los Angeles, appeared to have suffered a heart attack, a person with knowledge of the situation told The Associated Press. The person, who was not authorized to speak publicly and requested anonymity, said Jackson had a heart attack, which is a blocking of the arteries that deprives the heart of adequate blood.
Jackson's brother Jermaine said Thursday that it was believed the pop singer went into cardiac arrest, an interruption of the normal heartbeat that can be caused by factors other than heart attack. The Los Angeles County coroner's office, which completed its autopsy Friday, said there were no signs of foul play or trauma, but determining the cause of death will require further tests that will take six to eight weeks.
A heart attack could help explain why Jackson was in the care of a cardiologist while he went through vigorous training for an upcoming series of concerts in London: Heart attacks can indicate a long-term problem, such as heart disease. It would not necessarily rule out another factor, such as drug use, however.
Coroner's spokesman Craig Harvey said Jackson was taking some prescription medications, but did not specify what they were.
Police seized Murray's car the night before, saying they believed the car may contain drugs or other evidence, but have insisted that Murray has been cooperative and do not consider him a criminal suspect.
"We do not consider him to be uncooperative at this time," said police Deputy Chief Charlie Beck, noting that detectives spoke with the doctor after Jackson's death. "We think that he will assist us in coming to the truth of the facts in this case."
Records reveal years of financial troubles for Murray, who practices medicine in California, Nevada and Texas. His Nevada medical practice, Global Cardiovascular Associates, was slapped with more than $400,000 in court judgments, and he faces at least two other pending cases and several tax liens.
Beck declined to answer questions about how long the doctor had been with Jackson before paramedics were summoned, or if any drugs had been administered.
Phillips said AEG Live advanced Jackson money to pay for Murray's services as part of the production costs. Phillips said he asked Jackson why he wanted Murray with him full-time.
"He just said, 'Look, this whole business revolves around me. I'm a machine and we have to keep the machine well-oiled,' and you don't argue with the King of Pop," Phillips said.
The promoter said that sometime in February Jackson submitted to "five-plus hours of physicals that the insurance underwriter insisted on. We were told he passed with flying colors."
Based on those results and the nature of the comeback shows, all of which were to be held at the same venue from July 13 to March, AEG Live wasn't concerned about Jackson's history of medical issues.
"This wasn't as strenuous as a tour. There was no travel," Phillips said. "He and the kids were going to be living in this beautiful home outside London and shows were spread out over six months. For him, it seemed like the perfect way to come back."
Phillips attended Jackson's rehearsal at Staples Center on Wednesday night, when the entertainer was on stage for about three hours before leaving at 12:30 a.m.
"He was dancing as well or better than the 20-year-old dancers we surrounded him with," the promoter said. "He was riveting. I thought we were home free. I thought this was going to be the greatest live show ever produced. He looked great."
Phillips said AEG Live held multiple insurance policies covering cancellation of the shows.
"We had pretty good coverage, but a lot of it is going to depend on the toxicology results," he said. "We need to know what the cause of death was."
A 911 call released by fire officials Friday shed light on the desperate effort at the mansion to save Jackson's life before paramedics arrived Thursday afternoon. Jackson died later at UCLA Medical Center.
In the recording, an unidentified caller pleads with authorities to send help, offering no clues about why Jackson was stricken. He tells a dispatcher that Jackson's doctor is performing CPR.
"He's pumping his chest," the caller says, "but he's not responding to anything."
Asked by the dispatcher whether anyone saw what happened, the caller answers: "No, just the doctor, sir. The doctor has been the only one there."
Lou Ferrigno, the star of "The Incredible Hulk," said he had been working out with Jackson for the past several months. Still, Jackson's health had been known to be precarious in recent years, and one family friend said Friday that he had warned the entertainer's family about his use of painkillers.
"I said one day we're going to have this experience. And when Anna Nicole Smith passed away, I said we cannot have this kind of thing with Michael Jackson," Brian Oxman, a former Jackson attorney and family friend, told NBC's "Today" show. "The result was I warned everyone, and lo and behold, here we are. I don't know what caused his death. But I feared this day, and here we are."
Oxman claimed Jackson had prescription drugs at his disposal to help with pain suffered when he broke his leg after he fell off a stage and for broken vertebrae in his back.
The worldwide wave of mourning for Jackson continued unabated for the man who revolutionized pop music and moonwalked his way into entertainment legend.
"My heart, my mind are broken," said Elizabeth Taylor, who was one of Jackson's closest friends and married one of her husbands at a lavish wedding at the pop star's Neverland Ranch in 1991. She said she had heard the news as she was preparing to travel to London for Jackson's comeback show, and added, "I can't imagine life without him."
Scores of celebrities who knew or worked with Jackson â or were simply awed by him â issued statements of mourning. Some came through publicists and others through emotional postings on social networking sites like Twitter and Facebook, where countless everyday fans were sharing memories as well.
His two ex-wives both said they were devastated. One of them, Lisa Marie Presley, posted a long, emotional statement on her MySpace page in which she said her ex-husband had confided to her 14 years ago that he feared dying young and under tragic circumstances, just as her father, Elvis Presley, had.
"I promptly tried to deter him from the idea, at which point he just shrugged his shoulders and nodded almost matter of fact as if to let me know, he knew what he knew and that was kind of that," Presley said.
When he was on trial on child molestation charges in 2005, Jackson appeared gaunt and had recurring back problems that he attributed to stress. His trial was interrupted several times by hospital visits, and Jackson once even appeared late to court dressed in his pajamas after an emergency room visit.
After his acquittal, Jackson's prosecutor argued against returning some items that had been seized from Neverland, the Santa Barbara County estate Jackson had converted into a children's playland. Among the items were syringes, the powerful painkiller Demerol and other prescription drugs.
Demerol carries a long list of warnings to users. The government warns that mixing it with certain other drugs can lead to reactions including slowed or stopped breathing, shock and cardiac arrest.