Michael Jackson's children will reportedly lose most of their £900 million inheritance. The late singer's kids, Prince, 19, Paris, 17, and Blanket, 14, were due to inherit their windfall when they turn 30 but tax authorities are said to be seeking £555 million from the 'Thriller' hitmaker's estate. And Michael - who died of acute Propofol intoxication in June 2009 - is believed to have died with over £300 million in other debts. A source told The Sun newspaper: "On paper the kids are billionaires thanks to these massive sums. But the truth is those sums will barely be in their accounts for any time as they have this huge tax bill to settle. "The IRS (Internal Revenue Service) had been public about their demand asking for as much as £555 million, with more charges coming for late payments." The tax figure has just increased by around £70 million after Michael's state in Sony/ATVMusic Publishing was recently sold for £526 million. The source added: "The estate has challenged that enormous figure, but the Sony deal simply ups the amount they owe." It was recently revealed the King of Pop's children are missing something else from their inheritance as his treasured 'Gone With the Wind' Oscar has disappeared. The 'Bad' singer bought the 1940 Best Picture statuette for $1.54 million - considerably more than its $300,000 worth - at an auction in 1999, but executors of his estate are now unable to find the trophy. Lawyer Howard Weitzman said: "The estate does not know where the 'Gone With the Wind' statuette is. "We would like to have that Oscar because it belongs to Michael's children. I'm hopeful it will turn up at some point." It is unclear whether the 'Billie Jean' hitmaker kept the Oscar - which was awarded to legendary producer David O. Selznick - at his Neverland estate in California, the Los Angeles home he shared with his children when he died, or even at a storage facility.