Sales of norovirus-free oysters at the Cornish Shellfish Co have grown by 100% since an FSA study in November revealed that three quarters of all UK oysters carried the virus.

Cornish Shellfish has been selling its Cornish Assured shellfish for three years. But sales had grown to 3,500 oysters a week since September, a spokesman told The Grocer.

“Chefs like to serve oysters, but you cannot have customers falling ill, especially in high-profile, prestigious restaurants,” said a spokesman.

Cornish Shellfish purifies the oysters in tanks of recirculating sea water sterilised using UV light. They sell at roughly a 60% premium to standard oysters. Customers include Raymond Blanc’s Le Manoir aux Quat’Saisons and the chef patron pledged to use no others.

Though common, the norovirus vomiting bug is most closely associated with a severe outbreak of food poisoning in Heston Blumenthal’s Fat Duck in 2009.