International Major Deals

In September 2010, brothers Nick and Christian Candy – the English property developers behind One Hyde Park – sold a penthouse apartment in Monaco to an unnamed Middle Eastern investor for $314m (£198m).

Billionaire Russian tycoon and Chelsea football club owner, Roman Abramovich, is also a fan of the Cote d’Azur, which like Switzerland has seen a boom in high-end property prices in the past few years.

Villa La Leopolda, the 10-acre estate he is thought to have purchased from Microsoft mogul Bill Gates for $450m (£284m) is often described in the media as the world’s most expensive house.

But the truth is we will never know for sure. Many of the biggest property deals take place well away from the prying eyes of the media, and are not even listed in real estate agents’ guides, according to the experts