Rinat Akhmetov, Ukraine’s richest man, has emerged as the buyer of the historic Villa Les Cedres in the south of France.
More houses worth $25 million-plus were bought on Manhattan's 57th Street in the last five years than on any other road.
The Westminster City Council is concerned that mega-mansions will overshadow the needs of less wealthy residents.
Magnier, a former shareholder in English soccer club Manchester United, is a breeder of thoroughbred horses.