An autopsy performed Friday on the body of Michael Jackson was inconclusive, the Los Angeles County Cororner's office said. It may be four to six weeks before an official cause of death is established.
Los Angeles County coroner's spokesman Craig Harvey said there were no signs of foul play or trauma to the body. He confirmed that Jackson was taking some unspecified prescription medications.
Assistant Chief Coroner Ed Winter was with Jackson's family on Friday afternoon.
Jackson apparently suffered cardiac distress at his rented home in the posh Los Angeles neighborhood of Holmby Hills and died at UCLA Medical Center Thursday. The entertainment icon was 50 years old.
Earlier, authorities had said results were not likely to be final until toxicology tests could be completed, a process that takes several days and sometimes weeks. Police said they were investigating, standard procedure in high-profile cases.
"It is believed he suffered cardiac arrest in his home. However, the cause of his death is unknown until results of the autopsy are known," his brother Jermaine said.
The Los Angeles Police Department said Friday that it is searching for a doctor who may be able to help in the investigation of Jackson's death.
LAPD spokeswoman Karen Rayner says that police towed from Jackson's house a BMW owned by one of the superstar's doctors. "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."
Rayner said police did not know the doctor's identity, and she stressed that the doctor was not under criminal investigation but coroner's investigators wanted to contact him.
In a 911 call released by fire officials, a caller reports that Jackson was on a bed and not breathing or responding to CPR. The unidentified caller said Jackson was with his personal doctor at the time. The pop star died later Thursday afternoon at UCLA Medical Center.
Jackson's death comes as he was rehearsing for his first major concert tour in 12 years, scheduled to begin July 13 at London's famed 02 arena. He had been spending hours toiling with a team of dancers for a performance he and his fans hoped would restore his tarnished legacy to its proper place in pop. When tickets went on sale last March, they sold out in minutes.
There was some speculation, however, that he would not be up to the task physically. In 2005, he'd appeared gaunt and weak during his trial on child molestation charges. He later admitted an addiction to painkillers. After his acquittal, he kept a low profile, spending time in Bahrain, Ireland and France.
News of his death Thursday stunned nearly everyone, from the young man in Colombia who was named after the King of Pop to Malaysians who named a soy drink for him to a generation of people around the world who have tried to moonwalk.
Within minutes of Jackson's arrival by ambulance at the Medical Center, people began arriving by the hundreds. A crowd remained at sunset, hours later, some dancing while passing cars blasted out Jackson tunes. A group of entrepreneurs sold T-shirts reading, "In Loving Memory of Michael Jackson."
A White House spokesman said Friday that President Obama saw Jackson as a spectacular performer and music icon whose life nonetheless had sad and tragic aspects. The House of Representatives observed a moment of silence.
The grief crossed all borders.
"My heart is heavy because my idol died," said Byron Garcia, security consultant at a Philippine prison who organized the famous video of 1,500 inmates synchronized dancing to "Thriller." The video has had 23.4 million hits on YouTube.
Garcia said the inmates in Cebu will hold a tribute to Jackson on Saturday with their "Thriller" dance and a minute of prayer.
"I had tears in my eyes when I found out," Charles Winter, 19, from Adelaide, Australia, told The Associated Press. He led a Facebook group of more than 60,000 members that was petitioning Jackson to add Australia to his concert tour planned for this year. "He was such an inspiration. It doesn't matter if you're 40, 60 or 20, his music appeals to everyone."
In New York's Times Square, throngs of people gathered as word spread about Jackson's death and people began relaying the news by text messages.
The Apollo Theater in Harlem — the theater where Jackson first performed at age 9 — posted the message, "In Memory of Michael Jackson, A True Apollo Legend" on its billboard Thursday.
The troubled pop star's death brought very public expressions of grief in Asia, where he had many fans and had made several high-profile visits in recent years.
Japanese television interrupted regular programming to go live from the U.S. with coverage of the news. Former South Korean President Kim Dae-jung, who had met Jackson, said: "We lost a hero of the world."
Jackson's death received top billing on popular Internet portals in China, where the height of his stardom in the early 1980s coincided with China's opening to the world and its first post-revolution taste of American pop culture.
In Brazil, movie director and musician Felipe Machado called Jackson "perhaps the best performer that ever existed." Singer-composer and former Culture Minister Gilberto Gil also expressed his sorrow.
"It makes me very sad to see such a great and incredible talent leave us so soon — a talent that provided all of us with some wonderful moments," he told Folha Online news service. "I'll miss the King of Pop."