Michael Jackson taking off his shoes before entering the Swaminarayan Temple in Neasden, north London

London, June 26: The Jackson five of old became the Jackson four after the sudden death yesterday in Los Angeles of its youngest and most famous member, Michael Jackson, King of Pop, at the age of 50.

An autopsy was being conducted later by the Los Angeles coroner Jerry McKibben along with toxicology tests but the singer’s brother, Jermaine — he was the dignified one who supported Shilpa Shetty in her battle with the late Jade Goody on Celebrity Big Brother in 2007 — said that “we believe he suffered a cardiac arrest at his home”.

However, results are not likely to be final until toxicology tests are completed, a process that could take several days and sometimes weeks. If a cause can be determined by the autopsy, they will announce the results, said McKibben. Police added that they were investigating, standard procedure in high-profile cases.

The 50-year-old musical superstar died yesterday, just as he was preparing for a series of 50 concerts starting on July 13 at London’s O2 arena. He died at the UCLA Medical Center after being stricken at his rented home in the posh Los Angeles neighbourhood of Holmby Hills. Paramedics tried to resuscitate him for nearly three-quarters of an hour, then rushed him to the hospital, where doctors continued to work on him.

The Sun newspaper today reported that Jackson aides told medics at the UCLA emergency room that the star had collapsed after an injection of the drug Demerol, a powerful painkiller which is similar to morphine and which is known to come with the risk of cardiac arrest.

“Shortly after taking Demerol he started to experience slow shallow breathing,” the newspaper quoted one source as saying.

“His breathing gradually got slower and slower until it stopped.” No confirmation was immediately available on that report, but the celebrity website TMZ.com said that Jackson on Wednesday night attended a rehearsal at Los Angeles’s Staples Center to prepare for the London concerts.

Today, police towed the car of a doctor from Jackson’s home and said it could contain drugs or other evidence offering clues in the pop star’s death.

Los Angeles police spokeswoman Karen Rayner said coroner’s investigators were planning to interview the doctor but said she did not know the doctor’s identity. She stressed the doctor was not under criminal investigation.

Brian Oxman, a Jackson family lawyer and spokesman, told CNN that Jackson had been struggling to cope with the after-effects of various performance injuries, including a damaged vertebra and a broken leg, which had been interrupting scheduled rehearsal for the London dates. He went on to accuse those around Jackson of letting him slip into dependency on prescription drugs and painkillers.

“I can only tell you that this is not something which has been unexpected,” Oxman told CNN from the LA hospital as family members came to terms with the news from doctors. “This family has been trying for months and months to take care of Michael Jackson. The people who have surrounded him have been enabling him: if you think that the case of Anna Nicole Smith was an abuse, it is nothing to what we have seen taking place in Michael Jackson’s life.” He added: “I can tell you for sure that this is something I warned about. Where there is smoke there is fire.”

Jackson’s home was searched by detectives from LAPD’s Robbery Homicide division at the behest of city police chief William Bratton — although officers called it an “everyday” event.