The financial legacy of Michael Jackson, who died last week aged 50, will be made public once probate is granted – if the legendary singer made a will, an expert has said.

However, this will not be the case if the King of Pop established a trust during his lifetime, international inheritance expert Fernando Gandioloi told the Times.

If Jackson did not make a will then, providing he has no legal wife, his wealth will be inherited by his three children: Michael Jospeh Jackson Jr, 12; Paris Michael Katherine Jackson, 11; and Prince Michael II, 7.

There is huge speculation about the potential for a protracted legal battle over Jackson's business and music empire.

The Thriller star reportedly had debts of $400 million (£242 million) when he died, and the release of the contents of his will – if he made one – should indicate how his estate will be divided.

Jackson may have taken out a life insurance policy or transferred assets into a trust to protect some of his estate from creditors and manage the inheritance of his wealth among his children.

Although Jackson's extravagant behaviour led him to be branded 'Wacko Jacko', the entertainer made a shrewd investment in 1985 by buying ATV Music Publishing, which owned the Beatles' back catalogue, for $47.5 million.

His financial trust sold 50 per cent to Sony for $150 million ten years later, but Jackson's share at present is estimated to be worth $2 billion.

This weekend, Jackson's 2003 Number Ones album went to number one in the album charts and set a new record for fastest sales in one day.

Gennaro Cataldo, spokesman for music retailer HMV, said: "The demand for Michael Jackson hits has just been phenomenal – even more than when Elvis, John Lennon and Freddie Mercury died."

Philip Appleby of Rowlands Solicitors LLP comments "Michael Jackson's sudden tragic death shows us all the importance of making a will, especially if there are children involved. If no will is left then the Court decides who is to look after any children, so we would strongly recommend that anyone with a young family makes a will to ensure that appropriate guardians are nominated. Trusts can also be set up to make appropriate financial provision for children as they grow older."