Suffering from debilitating insomnia in the months leading up to his shocking death last week, pop icon Michael Jackson [Images] was 'adamant' about receiving a powerful intravenous sleep aid called Diprivan, also known as Propofol, according to interviews with Jackson's former nurse and nutritionist Cherilyn Lee.

Lee told CNN and the Associated Press that the 50-year-old Jackson was beset by severe insomnia as he rehearsed for his This Is It! run of 50 comeback concerts, set to begin July 13 at London's [Images] O2 Arena.

'He wasn't looking to get high or feel good and sedated from drugs,' she reportedly told the AP. 'This was a person who was not on drugs. This was a person who was seeking help, desperately, to get some sleep, to get some rest.'

When she refused to relent to Jackson's requests, he told her that another doctor had administered the drug to him in the past. Lee added that she never gave Jackson the drug, a powerful anaesthetic widely used in operating rooms to induce unconsciousness. Diprivan reportedly has a very small therapeutic window, meaning that it does not take doses much larger than the recommended amount to overdose, which can cause a person to stop breathing, leading to cardiac arrest.

Last Sunday, just four days before he died, one of Jackson's aides placed a frantic call to Lee and said that Jackson was extremely unwell. 'One side of my body is hot, it's hot, and one side of my body is cold,' Lee reportedly overheard Jackson saying in the background. Though she advised that Jackson be rushed to a hospital, he was not. Four days later, he died of suspected cardiac arrest. 'He was in trouble Sunday and he was crying out,' Lee told the AP.

Lee also said that, when she first met Jackson, he told her of his inability to sleep, and had her stay over in order to see for herself. Jackson went to bed with Western classical music playing on a sound system and popular cartoon Donald Duck playing on a computer, she said.

After managing to sleep for only three hours, Jackson told her, 'All I want is to be able to sleep. I want to be able to sleep eight hours. I know I'll feel better the next day,'' she added.

Speculation that prescription drug misuse played a role in Jackson's death has filled reports since his death last week. 'We know he was taking some prescription medication,' the coroner's office said when initial autopsy results were released.

Former Jackson family attorney Brian Oxman reportedly told Us Weekly, 'I warned them there was the misuse of prescription medications by people who were enabling him; his handlers, folks who should never have been permitted to allow him to use those medications in the manner I observed.'

The cause of Jackson's death will not be established until toxicology tests are returned, which could be another six weeks.