CONTAMINATED oysters from Colchester have been blamed for poisoning customers at a celebrity chef’s restaurant.

Colchester Oyster Fishery could face legal action after an official report found its shellfish were behind an outbreak of food poisoning at Heston Blumenthal’s restaurant, the Fat Duck, once voted among the world’s best.

A report by the Health Protection Agency said raw oysters from the firm, based in East Road, East Mersea, may have been contaminated with human sewage.

It said tests of the oyster beds showed they were infected with norovirus, which causes vomiting and diarrhoea.

Health inspectors said the supplier was also potentially linked to several other outbreaks of the bug.

More than 500 diners at the three Michelin-starred restaurant in Berkshire fell ill in January and February.

The investigation found a delayed response by the restaurant, the use of unsuitable cleaning products, and the early return to work of staff who had contracted the bug, exacerbated the impact of the outbreak, which lasted for six weeks.

Dr Graham Bickler, the HPA’s South East regional director, said: “This investigation has been long, complex and thorough.

“It confirms the well-known risks that raw shellfish pose.

“Oysters and other shellfish can become contaminated with norovirus originating from human sewage, especially during winter months. Individuals infected with norovirus can readily transfer the virus on to foods they prepare.

“The virus will remain viable and capable of causing illness in those foods that are not subsequently cooked. The more intensively food is handled, the more likely it is to become contaminated by infected food handlers.”

The Royal Borough of Windsor and Maidenhead, which investigated the incident along with the HPA, is now considering whether to take legal action.

Helen Taylor, the council’s communications officer, said: “Our investigation is complete and now, with the publication of the HPA report, we can finalise our conclusions.

“The decision whether to take further formal action will be based on these conclusions, and will be drawn only after careful consideration of all the available facts and conveyed to the Fat Duck.

“A timescale has not been set, however, we do not anticipate any unnecessary delay.”

The Gazette contacted Colchester Oyster Fishery, which confirmed it was the Essex source named in the HPA’s report. However, it has not made any further comment.

Colchester Council said it is required to test for viruses in Mersea’s oyster beds on a routine basis, but not for norovirus.