Round-the-clock protection for jewel-encrusted heels
The diamond-encrusted sandals carry a price tag of £650,000 and went on sale on Monday amid tight security.
The strappy high heels - which are size five, or European 38 - will be guarded round-the-clock behind bullet-proof glass.
They were made by US designer Stuart Weitzman and first worn to the Oscars last month by Mulholland Drive actress Laura Harring.
Model Heidi Wichlinski, ex-girlfriend of Formula One driver David Coulthard, slipped her feet inside them for photographers.
The 5ft 11in blonde told reporters: "Actually, they are extremely comfortable."
The shoes are woven from platinum thread, set with 464 diamonds in pure platinum.
Mr Weitzman assured potential buyers the shoes do not have to fit because they can be "deconstructed and remade to exact requirements".
The Knightsbridge store is used to selling expensive goods although not always successfully.
A £2 million Kojis diamond failed to sell despite being reduced by 50% when on sale to the bargain price of just £1 million.
If the diamond shoes are left on the shelf after two weeks on display, they will be returned to Mr Weitzman.