Rosenthal and wife among Fat Duck victims

Sports presenter criticises restaurant as Blumenthal is forced to delay reopening

Heston Blumenthal has again been forced to delay the reopening of his restaurant as environmental health officers extend their search for the cause of a stomach bug that has afflicted 40 diners.

About 500 guests have now had their reservations cancelled for the £130-a-head Fat Duck in Bray, Berkshire, while Windsor and Maidenhead Council checks the results of tests on its kitchen and ingredients.

Results received back so far this week have found no evidence of food poisoning but further checks are due before the restaurant can be given the all-clear, meaning it will stay closed until Friday at the earliest, two days later than first hoped.

As the council's investigation continued, one diner, the television sports presenter Jim Rosenthal, accused the chef's staff of treating him and his wife Chrissy poorly after they fell ill.

Rosenthal – who was celebrating his wife's 58th birthday with the boxing promoter Frank Warren and three other friends – said he was still ill two weeks after his first visit to the Fat Duck – one of only three restaurants in the UK with three Michelin stars – but had received little support from staff.

"I called the Fat Duck to tell them that after eating there all six of us had become ill. The manager called me back and told me he took the incident seriously. He did not point out that 40 others had also fallen ill, however – although he did put us in touch with Food Alert, a company which asked us to fill out a form.

"Since then, we have heard nothing," Mr Rosenthal told the Daily Mail. "A bowl of flowers for my wife to be sick into would have been nice."

Blumenthal's spokesman said that restaurant staff had followed normal practice and contacted the TV presenter twice following the incident.

Blumenthal, 42, whose Channel 4 series Heston's Victorian Feast began this week, is estimated to have lost about £100,000 since he closed the Fat Duck nine days ago. Last night Windsor and Maidenhead Council could give no timetable for the conclusion of its tests on samples of food and swabs of kitchen surfaces. Tests are also being carried out into whether any of Blumenthal's 42 chefs has a virus.

"Some tests have come back and they are negative but more results are expected," said Blumenthal's spokes-man. "It will re-open as soon as possible but it's entirely in the hands of the environmental health officers and they are being very thorough."

A council spokeswoman said the investigation "is still ongoing".