Police investigating a kitchen porter accused of poisoning soup at a top public school said today there was no apparent grudge or grievance that would suggest a motive for the act.
The 58-year-old was arrested last Friday on suspicion of administering poison with intent to endanger life or inflict grievous bodily harm after the carrot and coriander soup was found to be tampered with at Stowe School, Buckingham.
Police said the man was not interviewed as he was unfit to be detained due to health reasons. He was bailed until March 29.
At a press conference today at the £27,000-a-year school, headteacher Dr Anthony Wallersteiner said it is believed the product used was a "household cleaning product that would be used in any domestic kitchen".
In response to rumours the employee may have had some form of grudge against the school, he said: "From the discussions I have had with the line managers of the catering department we do not know of any grievances or previous issues with this individual."
Chief Inspector Henry Parsons, from Thames Valley Police, added: "Both the police and the school are not aware of any issues at all, any motive of this at this early stage."
Police said the incident is not believed to be terrorist-related at the moment.
Forensic investigations are continuing to establish what was put in the batch of soup.
Dr Wallersteiner said staff became suspicious during routine testing on Thursday that the carrot and coriander soup may have been tampered with.
He said: "This was a batch of soup that was being prepared for the evening meal and that was quite an ordinary batch of soup, there was nothing untoward about it.
"Before any meal is taken up from the kitchens to be served the food is tested, and it was during the routine sampling that one of the duty chefs discovered there was something acrid in the soup that was being prepared."
He said the soup was being prepared for an ordinary evening meal, not the annual Stowe International Dinner.
Dr Wallersteiner added that around 650 pupils have evening meals at the school, and as many who wanted the soup may have had it.
Dr Wallersteiner said the employee, who had worked for the school since January 2007, had since been suspended under the school's disciplinary procedure pending a full inquiry.
He has been instructed that under no circumstances may he enter the school premises, the school said.
He said: "This is clearly a serious - but isolated - allegation of food being tampered with.
"As a result of the testing procedures we have in place in the kitchen, it was detected early and an investigation was undertaken immediately.
"I would like to reassure parents that no pupil or member of staff was affected in the incident and, given the rigour of the procedures, neither the pupils nor staff were put at any risk."
He said the member of staff who tested the soup had tested a very small quantity and said "it was immediately spat out because it tasted so foul".
"I have been in contact with the medical centre and I have asked whether they have spotted any unusual entries regarding food poisoning or food-related illnesses and they have said that as far as they are aware there has been no unusual activity in the medical centre.
"We have had a couple of viruses and normal seasonal flus but nothing gastric or food-related.
"There's nothing to suggest it was anything other than a one-off."
He said all food is routinely checked at the school before any meal is served, mainly to check quality and taste.
"I think the chefs are pretty proud of the work they do and want to make sure they do a good job," he added.
He said the school has around 760 pupils, drawing from a national catchment area, with around 10-15% from overseas.
Past pupils are believed to include tycoon Richard Branson.
Mr Parsons said the investigation is in its early stages and forensic work is continuing.
He said forensic inquiries to establish what was put into the soup are onging, "but it is believed to be a household product".
"It's not believed to be terrorist related at the moment and it is a one-off isolated incident," he added.
Dr Wallersteiner said he had informed parents, adding: "We are pretty shocked and obviously disappointed that we are facing a police investigation into one of our employees and the actions he may have taken.
"We are doing everything we can to reassured staff, pupils and parents that the standards of the catering department remain as high as ever.
"No pupils have been withdrawn as a result of this and we are not expecting any to be withdrawn."