A valet, a wine cellar, a private spa, a panic room, and home cooking from a team of award-winning chefs: if these are on your list of must-have creature comforts, then here's the apartment for you.

A total of 86 flats at One Hyde Park, thought to be the most expensive residential development in the world, have been officially unveiled by the property duo, the Candy brothers. Prices at the highly anticipated Knightsbridge project start at £6.5m for a simple one-bedroom flat and soar to £140m for one of the penthouses. Averaging about £6,000 a square foot, the prices are higher than any other residential space, according to property experts.

City grandees including Lord Fink, the hedge fund guru, Ken Costa of Lazards, and Bernie Ecclestone of F1 joined international investors and celebrities including Gary Lineker, Andrew Lloyd Webber, and Theo Fennell at the launch.

The project is a joint venture between the Candys' Guernseybased vehicle, CPC Group, and Waterknights, a company owned by the Qatari prime minister, Sheikh Hamad bin Jassim bin Jabr Al Thani.