The outbreak of foot-and-mouth outbreak in Surrey could effectively be over by the end of the week if no new cases emerge, one of the Britain's senior microbiologists has said.
The highly infectious disease was found in livestock on two farms in Surrey, but tests on two other properties proved negative.
"If there's nothing more by the end of this coming week I think we can be pretty certain we are in the clear," Hugh Pennington, a bacteriology professor and one of the country's leading food safety experts, told the BBC.
John Oxford, one of the country's leading virologists, also told the broadcaster the outbreak was in effect "over".
But Mr Pennington said it was important not to relax protection and surveillance measures.
As a result of the outbreak, more than 570 animals have been destroyed, and the European Union and individual countries have banned British meat and dairy exports.
Farmers say the trade curbs are costing them £1.8 million a day.
A severe outbreak of foot-and-mouth disease in 2001 forced the slaughter of six million animals and inflicted billions of dollars of losses on farmers and the tourism industry, as much of the countryside was closed to visitors.
Inspectors are continuing to trace the potential source of the disease, with a research facility at Pirbright in Surrey that was developing foot-and-mouth disease seen as the probable source of the outbreak.