Four people have been hospitaliszd after an outbreak of salmonella at a Darlington pub that also led to another 15 people falling ill.
The Copper Beech pub, in Neasham Road, has voluntarily stopped serving food after a number of cases of the infectious disease were linked to its kitchens.
Officers from the Health Protection Agency (HPA) have started an investigation to discover the source of the outbreak, which they believe has now been contained.
A spokesman for the pub, which is owned by the Punch Taverns chain, said the licensee had co-operated fully with the investigation and had closed the kitchens as soon as a possible link was identified.
He said the kitchens have now been cleared for re-opening by environmental health experts, but the pub has chosen to wait until the source of the infection is identified.