Chief vet: No plans to vaccinate

"We will look at this day by day by day," she told reporters in London.

She also said results of tests were not ready yet in the case of a farm near Dorking in Surrey which is outside the original exclusion zone put in place by the Department for Environment, Food and Rural Affairs (Defra).

Dr Reynolds said arrangements for possible vaccination were triggered immediately under the contingency plan.

"Vaccination is used if it is demonstrated that steps additional to slaughter policy may be required to eradicate disease," she said.

It had been decided not to vaccinate at this time. As for the farm at the centre of the latest scare, she said tests were under way.

Meanwhile, Defra said livestock culled on Hunts Hill Farm, the third farm within the protection area in Surrey, did not have foot and mouth disease.

Hunts Hill, owned by the Emerson family, is adjacent to the second farm contaminated with the disease in the village of Normandy, Surrey.

Defra took the decision on Wednesday to destroy cows, sheep, pigs and goats on the premises.

The animals were slaughtered on suspicion of having foot and mouth, but tests have since proved they did not have the disease.