Meanwhile, many conspiracy theories have come up as to what led to Jackson's sudden death. People close to Jackson have already claimed the role of ÒenablersÓ, who encouraged his dependency on prescription drugs.

ÒI do not know what medications he was taking, but the reports that we have received within the family are that they were extensive. I do not know the cause of it. But it is something that I feared. This is a case of abuse of medications, unless the cause is something else,Ó Brian Oxman, Jackson's attorney and spokesman had said.

Reports suggest the singer was working hard for his much-hyped 'This Is It' comeback concerts in London and he was taking prescription drugs to get into shape for the 50-date concert tours from July 13.

ÒHe was injected three times a day with Demerol, the potent painkiller given to him before his collapse at home in Los Angeles on Thursday,Ó British newspaper Sun said citing sources.

Reports in British media also suggest that the singer was worried about his mounting debt and was ÒterrifiedÓ about his comeback tour stating that ÒIf I don't do it, they will kill me.Ó

ÒHe kept saying that he had to do the concerts because he owed too much money,Ó a source close to the star said.

ÒHis friends say he signed his death warrant when he put pen to paper for the O2 shows. He wasn't up to it physically or mentally,Ó the source added.

Wall Street Journal quoting unnamed sources said Jackson had a debt of USD 500 million.

Though, the exact circumstances of singer's death remains unclear, the identity of the doctor, who reportedly administered CPR (Cardiopulmonary Resuscitation) has been revealed.

Dr Conrad Murray who is licensed in Texas, Nevada and California, is said to have administered CPR to Jackson on Thursday before the paramedics team arrived at his home. Murray also accompanied the singer to the hospital.

Mystery surrounds the identity of the person, who called 911 (US emergency number) after the singer collapsed.

ÒHe's not responding to CPR. He's (personal doctor) pumping his chest, but he's not responding to anything,Ó the caller had said, according to the transcript released by Los Angeles Fire Department.

The doctor's vehicle has been impounded by the police with Deputy Chief Charlie Beck saying that this was aimed at ascertaining whether there was any evidence relating to Jackson's death.

However, Beck declined to say whether detectives found medication in the car.

Murray was interviewed by police officials, who plan to quiz him again.

ÒNothing suggests criminality at this point,Ó Beck said about the investigation.

Tohme Tohme, Jackson's former manager said in an interview that AEG Live, the Los Angeles-based concert promoter behind Jackson's shows, had hired Murray.