A butcher's shop has closed temporarily while public health officials investigate an outbreak of the potentially fatal E.coli bug.

There are nine confirmed and eight unconfirmed cases of the infection and, at the time the Advertiser went to press, one person was being treated in University Hospital, Durham.

At one point four people were in hospital. Most of the cases are said to involve people from four households. The victims are aged one to 75.

Inquiries are centering on cold cooked meat sold by Castle Bank Butchers, Front Street, Chester-le-Street, but investigators are looking at other possibilities and are trying to trace the affected meat's supply chain.

Owner James Higginson voluntarily closed the shop. His other shops - at Esh Winning, Crook, Stanhope and Corbridge, Northumberland - are not affected.

The outbreak of E.coli 0157 was revealed at the weekend by the Outbreak Control Team, made up of officials from local health authorities and the district council. Symptoms range from mild diarrhoea to a severe illness that can lead to kidney damage/

E.coli 0157 can be found in the intestines of many healthy animals. Meat or milk can become contaminated during the slaughter or milking of animals and the bacteria are not killed by cooking or pasteurising.

The result of laboratory tests is expected to be known next week.

Discussions are ongoing about whether the shop can reopen.

Outbreak Control Team chairman Dr Deb Wilson said: "We are advising that as a precaution, any cooked meats bought from Castle Bank Butchers should not be eaten and should be thrown away.''

Dr Tricia Cresswell, director of public health for the Durham and Chester-le-Street Primary Care Trust, said: "When we identify a possible link to cases of E.coli we investigate the entire chain of production.

"We are talking about a relatively small number of cases and a possible link to one premises.

"There is no reason to think that other members of the public are at risk.''

Chester-le-Street Council says its environmental health officers have been inundated with calls from concerned members of the public.

Mr Higginson, who lives at Witton-le-Wear, has declined to comment about the outbreak.

Health officials are advising that anybody who develops severe diarrhoea or diarrhoea with blood should call their GP or out-of-hours service or ring NHS Direct on 0845 4647.