Lawyers for Michael Jackson and his family on Sunday prepared to square off in a courtroom hearing over control of the singer's estate as media reports mounted about powerful drugs that may have contributed to his death.

One legal expert predicted the existence of a 2002 will signed by Jackson means his mother, 79-year-old Katherine Jackson, will likely be forced to give up temporary control she now has over his affairs.

"Given the existence of the will and the expression of Michael's intentions, the only likely outcome is Katherine's powers will be terminated and she will no longer have any power to deal with the estate," Los Angeles-based family law attorney Michael G. Dave said on Sunday.

Lawyers for Katherine Jackson and for two men named co-executors of the will -- attorney John Branca and music executive John McClain -- that surfaced late last week will meet in Los Angeles Superior Court on Monday.

Katherine Jackson was granted temporary administrator of her son's affairs last week before the will became known.

It puts his estate, which in an attachment is valued at more than $500 million, into a family trust that benefits his three children, his mother, and charities.

Jackson died as much as $500 million in debt according to media reports, but he had assets that have been valued as high as $1 billion and include part ownership in a music catalog of songs from the Beatles and other recording artists.

Reports of drug use mount

A separate hearing over the guardianship of Michael Jackson's children has been postponed until July 13.

Katherine Jackson has been named temporary guardian of Prince Michael Jackson Jr., 12, Paris Michael Katherine Jackson, 11, and Prince Michael Joseph Jackson, II, 7, and the 2002 will also makes her guardian of the children.

Meanwhile, more media reports surfaced over the weekend about possible drug use by the 50-year-old "King of Pop," who died on June 25 when he went into cardiac arrest at his rented mansion in a wealthy Los Angeles neighborhood.

Several media reports have said the powerful anesthetic Diprivan was found in the home, and the Los Angles Times reported that a police probe is focusing on the role doctors may have played in providing Jackson with medication.

"Numerous bottles," of Diprivan without labels were found at the mansion, according to the Los Angeles Times.

Criminal defense attorney and legal expert Steve Cron said police will try to determine if any doctors who prescribed the medication were regularly examining Jackson.

"The step everybody is waiting on, is the autopsy report to show what was in (Jackson's) system," Cron said.

Two autopsies were performed on Jackson after his death but toxicology results are not expected for about a month.

Diprivan, the brand name of propofol, is an anesthetic that "should never be used outside of a controlled and monitored medical setting," the American Society of Anesthesiologists (ASA) said in a statement, noting that its members have not studied the particulars of Jackson's death.

Patients can have extremely variable responses to the drug and some patients can become completely anesthetized, including losing the ability to breathe, the group said.

Elsewhere, officials planning a massive public memorial for the singer on Tuesday in Los Angeles said about 1.6 million people registered to be one of 8,750 people who will get two free tickets to attend the service.

Details of the event and a private, family memorial service have not yet been released.

(China Daily/Agencies July 6, 2009)