Mr Blumenthal is said to be "fanatical" about food hygiene
Sabotage has been ruled out as an explanation for a food poisoning scare at a Michelin-starred restaurant owned by chef Heston Blumenthal.
He shut down the Fat Duck in Bray, Berkshire, last Tuesday after up to 40 patrons reported feeling unwell over the past two to three weeks.
Test have been carried out while the restaurant has been closed.
The chef's spokesman said sabotage was "highly unlikely" as cases of illness were "not sweeping but sporadic".
He added: "On a table of six, maybe only three people would get sick, so it could hardly be sabotage."
Tests by the celebrity chef's own food safety consultants and environmental health officers from Windsor and Maidenhead Borough Council have so far failed to find a cause for the guests' symptoms.
"We are waiting for the final test results to come back but all results so far have been completely negative," the spokesman said.
"It is highly unlikely that someone would be able to sabotage the food.
"He [Blumenthal] is well known for his precise, scientific concoctions which would be very hard to sabotage.
"All this leads us to believe that it [the health scare] has not come from the restaurant and we expect to be given the all clear."
Mr Blumenthal said he was baffled by what had happened.
"The whole thing is really upsetting and perplexing," he said.
"We have done so many tests but nothing has shown up.
"We called in the environmental health and I took the decision to close the restaurant.
"All of our checks were clear but if there is a problem then the restaurant has a duty to try and find out what it is."
The chef had to cancel 450 bookings but hopes to reopen the restaurant on Wednesday.
Mr Blumenthal researches the molecular compounds of dishes to achieve a greater understanding of taste.
Diners at the Fat Duck - one of only three restaurants in the UK with three Michelin stars - can experience dishes such as snail porridge or sardine on toast sorbet.
But they need to book months in advance to secure a table at the restaurant, where the tasting menu costs £130 .