A three-year-old boy has contracted e-coli food poisoning and 31 of his classmates have been sent home after going down with a gastro-intestinal illness.

Five of the 28 members of staff at the Bradford day nursery have also contracted the stomach bug which has spread during the past two weeks, causing vomiting and diarrhoea.

The situation was reported to the Bradford NHS Health Authority on Monday and a spokesman said the e-coli sufferer, from Brighouse, was recovering at home with family.

The health authority refused to name the nursery.

He was admitted to a Calderdale hospital on Friday but has now been released. Other members of his family are undergoing routine tests but none is thought to be seriously ill.

Dr Ruth Gelletlie, pictured, consultant in communicable disease control for the authority, said: "At the moment we have no reason to assume this illness is linked to the gastro-enteritis in the nursery.

"Several members of the child's family have had similar symptoms and the source of the illness is being investigated."

Dr Gelletlie said the e-coli case was not being linked to an outbreak in Calderdale and Bradford in June, which saw 17 people from the area undergo medical treatment.

She added: "We are monitoring the situation closely and parents have been informed about the outbreak. They will be informed immediately if there is any cause for concern."

The nursery, which cares for 105 children up to the age of five years, remains open and environmental health experts have given advice to staff and pupils.