The health scare that led to the closure of Heston Blumenthal's Fat Duck restaurant may have been caused by the norovirus vomiting bug, the chef says.
The Michelin-starred Fat Duck, in Bray, Berkshire, was shut for more than two weeks from 24 February after 400 diners complained of having fallen ill.
Blumenthal, 42, told Australia's Hospitality magazine that the cause was "categorically not food poisoning".
He said a number of customers and staff "had tested positive for norovirus".
Norovirus, known as the "winter vomiting disease", is the most common cause of stomach bugs in the UK.
The virus, which causes sudden vomiting and diarrhoea, is easily transmitted from one person to another by contact with an infected person or through contaminated food or drink or touching contaminated surfaces or objects.
Speaking to Hospitality magazine after arriving in Australia for the Melbourne Food and Wine Festival, Mr Blumenthal said: "The only thing that has come up is that three staff and five customers have tested positive for something called norovirus."
He said support for the restaurant had been "incredible" but it had been a costly experience for the restaurant.
"It's affected the restaurant big time because we had to cancel 800 people because of the closure but in terms of the business and people wanting to come in then no," he said.
The celebrity chef added: "For the last five years we've been sending food off every month for sampling and I don't know any other restaurant in the country that does that.
"We also have a company that has been looking after all our health and safety stuff for the last five years."
Earlier this month, the Health Protection Agency (HPA) said the number of cases of reported illness among customers, going back to late January, had risen to about 400 since initial media coverage of the outbreak.
But the HPA said the restaurant was safe to re-open for business last week.
A spokeswoman for HPA's Thames Valley Health Protection Unit said: "Results of some tests are still awaited and the detailed questioning of people who reported illness is likely to continue for some weeks in order to build a more complete picture."