LOS ANGELES, July 1, 2009 (AFP) - A powerful drug commonly used as a general anesthetic before surgery was discovered by investigators at Michael Jackson's home, the TMZ.com celebrity news website has reported.

Citing unidentified sources, TMZ said Tuesday the drug Propofol was found at Jackson?s rented mansion following his death from an apparent cardiac arrest last Thursday at the age of 50.

The website described the drug as an "extremely dangerous and potent" substance which was only available to medical personnel.

"There is no conceivable way this drug can be properly prescribed for home use," a source told the website.

Earlier, a former nurse who cared for Michael Jackson told CNN Tuesday the pop star pleaded with her to provide him a powerful sedative in the last months of his life.

Cherilyn Lee, a health practitioner with more than 20 years experience, said Jackson had requested the drug Diprivan. Lee, who claimed to work for Jackson for three months between January and March, said she refused his request.

Lee also revealed that a member of Jackson's staff had requested the drug four days before the singer's death last Thursday.

Lee said she had turned down the request after warning the singer of the side effects.

"I told him this medication is not safe," Lee said. "He said, 'I just want to get some sleep. You don't understand. I just want to be able to be knocked out and go to sleep.'"

"I told him - and it is so painful that I actually felt it in my whole spirit - 'If you take that you might not wake up.'"

CNN said it could not independently verify whether Lee had worked for Jackson. Lee was also unable to explain why she was contacted by Jackson's staff last week more than three months after she had ceased to work for him.

Several friends and associates of Jackson have said the singer had easy access to powerful prescription drugs and they may have contributed to his death.