There were growing fears tonight that the outbreak of foot and mouth disease on a farm in Surrey in England was caused by a leak from a nearby animal research laboratory.
Officials from the British Department for the Environment, Food and Rural Affairs (Defra) said the strain of the virus detected in infected cattle was the same as one being used at the Pirbright laboratory a few miles from the infected area.
They said the strain was not one recently found in animals but was similar to ones used in diagnostic laboratories and vaccine production.
They could not say definitely that the laboratory was the source of the disease but immediately increased the size of the protection and surveillance zones covering farms in the area.
All 60 cattle in the affected beef unit in Surrey have been slaughtered. A three kilometre protection zone, and a 10km surveillance zone, have been imposed around the farm.
Britain's Department of Agriculture says it is also investigating other possible cases of foot and mouth but said that no other outbreaks have been confirmed.
Britain has banned all movement of pigs, sheep and cattle and all exports of animal carcasses, meat and milk to European Union countries and British Prime Minister, Gordon Brown, has cut short his holiday to oversee the response to the outbreak.
Here the Minister for Agriculture, Mary Coughlan, has banned the importation of all live animals, fresh meat and non-pasteurised milk from Britain in response to the confirmed outbreak.
Taoiseach Bertie Ahern and Northern Ireland First Minister Ian Paisley have agreed that there will be full co-operation between the North and the Republic to ensure that foot and mouth is kept off the island of Ireland.
Earlier today, the two Irish Agriculture Ministers, Mary Coughlan and Stormont Agriculture Minister Michelle Gildernew vowed to maintain close contact.
Minister Coughlan urged farmers to be vigilant but said there are no plans yet to ban sports events or public gathering.
Minister Gildernew said the Northern Assembley would mirror the action taken by the authorities in the Republic to ensure the country became a fortress against the potential spread of the disease here.
