New court papers filed by the late 'Thriller' star's lawyers show the huge sum was spent on Prince, 18, Paris, 16, and 13-year-old Bigi - who was previously known as Blanket, though his real name is Prince Michael II - two years ago, with expenses including £290,000 on a house in Calabasas, California, which is rented for the kids at the cost of £22,000 a month.

A total of £48,000 in fees for Buckley School was also spent for Prince and Paris, before the latter dropped out, with £19,000 also being spent on a separate school for ''young performers'' according to The Sun newspaper.

Other expenses included chartering a private plane for £90,000, £300,000 on staff at their properties as well as £30,000 on other workers, £600 on Bigi's 11th birthday bash and £274,000 for a trip to Hawaii with Prince and Paris' biological mother, Debbie Rowe.

The children are cared for by the music icon's 85-year-old mother Katherine, whose Hayvenhurst home has been purchased by the estate and renovated for in excess of £380,000.

Michael - who died of cardiac arrest in 2009, aged 50 - left £320 million worth of debt when he passed away, although his assets have been valued at £160 million, with others suggesting they could be worth over £1 billion.

The three children are set to inherit equal shares of the estate, but not until they reach the age of 33, where they will receive half, with the rest being given to them aged 40.