LONDON - The fact that Michael Jackson had suffered a heart attack was kept secret for as long as three hours to cover-up the real cause of his death, says a friend of the late superstar.

Dr. Steven Hoefflin, a friend of the singer, revealed the latest twist after speaking to medics involved in Jackson’s case.

“They say he had lividity, which means his blood had already sunk to the back of his body. This indicates Michael’s heart had stopped hours earlier,” the Mirror quoted him as saying.

It is also believed that the late King of Pop’s dead body was then moved to his bedroom so that the police would think that he killed himself with a fatal dose of the drug Propofol.

According to reports, experts at the coroner’s office believe that Jackson was moved after his heart attack, as they discovered disruptions in the pattern of “livor mortis” on his body.

Purple marks on his body show where blood has settled in a lifeless body, which usually takes at least five hours to become apparent.

Forensic pathologist Dr. Cyril Wecht, not involved in the Jackson case, said: “If someone carried the body from one room to another, the livor would be ‘broken’ where contact with the body was made. If one person held his ankles and the other held him under his arms, there would be corresponding white interruptions of livor mortis in those spots.”

Retired FBI special agent Ted Gunderson, who has independently monitored the case, said that the new evidence pointed to a “massive cover-up” by Dr. Conrad Murray, the late King of Pop’s personal doctor.

It may be recalled that the coroner has ruled that the ‘Thriller’ hit-maker was a victim of homicide after the strong sedative caused his cardiac arrest, and that investigators are probing whether Dr. Murray had any role in his death.

Gunderson asked: “Did Murray try to fool people into thinking Jackson died on the way to hospital in the hope an autopsy could be avoided? If so, it didn’t work, which is why he had to confess to administering Propofol.”

Meanwhile, Murray, 56, has denied mistreating Jackson. (ANI)