HOPES that the foot and mouth outbreak had been contained were dealt a blow today after a new suspected case of the virulent virus was discovered.

A 3km temporary control zone has been set up around undisclosed premises in Surrey, outside the existing surveillance area, after an "inconclusive assessment" of symptoms in cattle, said the Department for Environment, Food and Rural Affairs (Defra).

Chief veterinary officer Debby Reynolds said: "This is a developing disease situation.

"The containment and eradication of foot and mouth disease remains our priority. This is why we have moved swiftly to put in place a temporary control zone while we investigate this development.

"At this stage disease has not been confirmed, laboratory results will follow."

The new zone is to the west of Dorking and close to the two confirmed cases of the disease.

Ms Reynolds, breaking off from a late-night meeting, said: "It's a clinical suspicion and as a precaution we are putting in a temporary control zone, three-kilometre radius around the farm."

In the original outbreaks, the infected cattle had been grazing at two sites in the village of Normandy, near Guildford, which is close to a research facility in Pirbright, Surrey.

Investigations into the cause of the outbreak have focused on this establishment as the laboratory is shared between the Institute for Animal Health, a diagnostic and research centre, and the pharmaceutical company Merial Animal Health, whose work includes manufacturing vaccines.

Hugh Broom, of the National Farmers' Union, said the suspected case was "very worrying" and urged farmers to keep on top of biosecurity.

He added: "Farmers in Surrey are taking biosecurity seriously and we would urge them to keep that up regardless of who is to blame.

"It won't come as welcome news if a third case is confirmed in the county. It will be worrying for members here and farmers elsewhere in the country."

The suspected new case comes as a scientist helping to investigate the cause of the outbreak suggested the infections may have been caused deliberately.