Thousands of mourning fans will besiege Michael Jackson’s Neverland ranch on Friday after his family announced plans for a public wake.

The family will hold a private memorial service at the 2,500-acre estate in Santa Barbara County, California, on Sunday. Plans for Jackson’s funeral remain unclear.

At its height, Neverland featured its own amusement park, a zoo with giraffes and tigers and statues of children at play. He left the estate after his acquittal on charges in 2005 that he molested a 13-year-old boy there.

Thomas J. Barrack Jr, the Los Angeles billionaire whose company owns a majority stake in Neverland, issued an open letter to the Santa Barbara community urging them to welcome Jackson fans. Many objected to hordes who arrived in 2005 during Jackson’s most recent child abuse trial. Mr Barrack took control of Neverland in November as Jackson faced foreclosure.

Jackson left the estate to his children, his mother and children’s charities, according to reports. The pop star left nothing to his father, Joe, whom he accused of abusing him as a child.

The existence of a will, drafted by Jackson in 2002, has emerged as his parents swiftly moved to take control of his assets in court.

The Wall Street Journal reported that Jackson’s former lawyer, John Branca, wrote the will and he could file it to the probate court this week. Mr Branca is named as an executor, as is the music executive John McClain.

The news will complicate the looming court battle over the assets. His parents have asked a judge to make Katherine Jackson, the star’s mother, administrator of his estate.

The family want to take charge of his debt-ridden but potentially lucrative financial empire and act as permanent caretakers of his three children. In documents filed in the Superior Court in Los Angeles, Jackson’s parents said they believed that their 50-year-old son died without a valid will.

In the documents Burt Levitch, an attorney for Mrs Jackson, stated that others hold documents, including a will, that could work “to the detriment of the estate”. Jackson claimed to have a net worth of $236 million (£143 million) in 2007, according to documents obtained by the Associated Press.

Jackson had $567.6 million in assets, including Neverland, his share of the Sony/ATV Music Publishing catalogue, which includes the rights to songs by the Beatles, and an assortment of cars and antiques, according to a statement of financial condition by the accounting firm Thompson, Cobb, Bazilio & Associates.

The report says that Jackson had debts of $331 million, leaving him with a net worth of $236.6 million. He had just $668,215 in cash, according to the report, which is dated June 12, 2007.

A judge granted Mrs Jackson, 79, temporary guardianship of Michael Joseph Jackson Jr, known as Prince Michael, 12, Paris Michael Katherine Jackson, 11, and Prince Michael II, 7. Court papers state that she intends to use her late son’s assets exclusively for his children “after payment of debts and expenses of administration”.

The judge also granted Mrs Jackson the right to take control of her son’s personal property.

The judge did not immediately rule on her requests to take charge of the children’s and Jackson’s estates. A hearing is scheduled for Monday.

Investigators have retrieved medication from the rented mansion where the star collapsed last week. Coroner’s investigators and police detectives spent hours in the house and emerged with two bags filled with evidence.

The coroner’s office performed a post-mortem examination on Friday but deferred a finding on the cause of death, ordering toxicology tests. A second, private post-mortem has been requested by the family.

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