Gary Rhodes' last remaining UK restaurant, Rhodes @ the Dome, in Plymouth has been slapped with a score of zero under the Food Hygiene Rating Scheme.
The business was rated by inspectors from Plymouth City Council on 4 June 2015 and was given the score of zero, which denotes "urgent improvement necessary".
A spokesperson for the council said: "The zero food hygiene rating means that we have been working with Rhodes @ The Dome to make sure that they improve. Immediate action has been taken to remedy issues that pose an imminent risk to public health and we always revisit every zero-rated business on more than one occasion after the initial inspection, ensuring that we take enforcement action if necessary to secure compliance with food legislation.
A statement from Rhodes @ The Dome given to the Plymouth Herald, said: "Rhodes @ The Dome operates to the highest environmental health standards and probably has one of the most advanced food technology kitchens in the region - the low score relates to not having a head chef in post at the time."
A new head chef was reportedly being trained at the time of inspection, meaning no one was available to demonstrate an in-depth knowledge of food hygiene.
The restaurant said it was expecting a retest soon and anticipated a score of five out of five.
The restaurant, which opened in early 2013, is run for Rhodes, who now lives in Dubai, by local restaurateurs.
It hit trouble early last year when the company that operated it, RTD1 Ltd (later renamed Rhodes @ The Dome Ltd), entered voluntary liquidation.
The company had been run by local restaurateur and former professional rugby player Ed Steven, who used it to help set up the 150-cover restaurant in what used to be a museum building on Plymouth Hoe, overlooking Plymouth Sound.
However, the running of the restaurant was subsequently taken over by a new operating company called The Dome (Plymouth) Limited.
The company, which earlier this week filed accounts for a dormant company, now has just one director in the shape of John Steven, Ed Steven's father. It is not known if this company is still used as the vehicle to operate the restaurant.
John Steven is a veteran of the hospitality industry, having owned and run pub firm Wykeham Inns, which ran six sites and also held a lease on the Dome, until the business entered administration during the recession in 2008. The company subsequently handed back the lease of the Dome to its owner.