Fire ripped through Richard Caring's Chelsea restaurant Daphne's yesterday ahead of its lunchtime service.
Around 20 firefighters were called to the scene after the alarm was raised just before 11am, when a fire started in the kitchen's extraction system.
Dan Hallissey from the London Fire Brigade told the Evening Standard that access to the fire was difficult and the crews worked hard to bring it under control as quickly as possible.
The fire still burned several hours after it was reported, but it is understood it was confined to the vents in the restaurant. Fire crews used cherry pickers to tackle the blaze.
The restaurant's manager, who asked not to be named, said he was not yet aware of the extent of the damage or for how long it would require the business to close.
Last year the millionaire entrepreneur also backed new Soho restaurants Grillshack and Jackson + Rye, both led by Hannah Bass and Mark Askew.