world's most expensive flat which costs £100million in central London

The computer-generated picture visualises the £100 million One Hyde Park penthouse, the most expensive flat in the world, upon completion in 2010.

Other homes in One Hyde Park, Knightsbridge, have already sold at record prices of £6,000 per square foot.

Russian oligarchs, oil barons, Saudia princes and A-list stars are among those said to be buying the Candy brothers apartments.

The most expensive penthouse apartments will feature bullet proof windows, purified air systems and "panic rooms" and everyone on site will have access to an underground passage leading to the nearby Mandarin Oriental hotel.