New York City ? It’s one of the biggest mysteries in the Michael Jackson saga: How much was the lavish-spending, massively debt-ridden pop icon really worth?

In the most detailed account yet of the singer’s tangled financial empire, documents obtained by The Associated Press show Jackson claimed to have a net worth of $236.6 million as of March 31, 2007. But less than $700,000 of that amount was in cash — a relatively paltry sum given his opulent lifestyle, prodigious borrowing and seven-figure shopping sprees.

The dollar amounts, which previously consisted of estimates, are crucial because Jackson’s estate is expected to become the focus of a legal battle between the singer’s family and creditors.

Since then, however, Jackson’s debts and assets have grown substantially — he took on more debt in a refinancing transaction later that year, and the Sony/ATV Music Publishing joint venture spent hundreds of millions acquiring new songs.

Jackson had $567.6 million in assets, including his Neverland Ranch and his share of the Sony/ATV Music Publishing catalog, which includes the rights to songs by the Beatles, according to a statement of financial condition prepared by Washington, D.C.-based accounting firm Thompson, Cobb, Bazilio & Associates.

The report was prepared at a time when Jackson had large sums of debt coming due that had to be refinanced. The financial statement, which is not as thorough as an audit, was based in large part on estimates provided by Jackson’s advisers that the accounting firm said it could not verify.