Hopes that the foot-and-mouth outbreak had been contained were dealt a blow late last night when a new suspected case of the virulent virus was discovered.

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

Debby Reynolds, the Chief Veterinary Officer, said: “This is a developing disease situation and we have moved swiftly to put in place a temporary control zone while we investigate.

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

The new 3km zone is east of the existing surveillance zone and southwest of Dorking.

The precautionary measure comes after an inconclusive assessment of clinical symptoms by Animal Health veterinary staff. The national movement ban remains in place.

The suspected new outbreak came as a scientist called in to investigate whether the virus had escaped from an animal health research plant said yesterday that sabotage was fast becoming the only explanation.

Andrew King, who was brought in by the Institute of Animal Health (IAH), in Pirbright, Surrey, suggested that it was time to call in the police.

Dr King, a former head of molecular biology at the IAH, said that biosecurity was so tight that he felt the outbreak had to have been caused deliberately. He told The Times: “As far as I am concerned the authorities have failed to find any chink in the armoury of the establishment’s bio-security. What you are left with is human movement, which is not a matter for the institute, it’s a police matter. It’s very, very unlikely that it could be spread by accident. People do not spread the disease easily.”

Health and Safety Executive (HSE) staff, investigating how the virus infected at least two farms three miles from the Surrey complex, concluded in their preliminary report that human movements, either deliberate or accidental, were the most likely means by which the FMD virus escaped from laboratories with strict biosecurity measures designed to prevent leaks. The IAH and Merial, the American company that shares the same site at Pirbright, were named as the two most probable sources of FMD, but investigators have so far been unable to find any evidence that the biosecurity procedures and equipment were faulty.

Dr King said he thought it likely that Merial would also be given a clean bill of health. “That establishment is inspected by Defra every six months. Defra grants the licence. Defra says it’s OK,” he said.

He described a range of biosecurity measures to protect against leaks, including staff in contact with viruses having to shower and change all clothes. “None of these single measures is absolute but together it makes it impossible for the virus to get out and it never has got out in the modern era,” he said. “It has to be regarded as a bit fishy.”

Dr King added that the longest period after which the virus had ever been recovered from the human body after heavy exposure was 48 hours, and that involved a full body search. To pass the virus from human to cow “you would have to hug a cow and breathe down its nose”, he said.

Concerns that the FMD outbreak was caused by live virus escaping into the environment via the Pirbright research facility’s drainage system were effectively ruled out last night. Martin Shirley, IAH director, said that measures to ensure viruses did not enter the water system from his organisation were working properly. A back-up effluent treatment system that further treats water leaving the IAH and Merial had no reported problems.

Animal health workers were yesterday awaiting the results on tests of animals at a third farm in Normandy suspected of having FMD.

A total of 576 animals had been culled by yesterday, 362 of them from the third farm linked to the outbreak, to stop the spread of the disease.

The Pirbright facility was also at the centre of a second inquiry yesterday after a worker was admitted to hospital suffering from legionnaires’ disease. The subcontractor had been working at a building at the IAH shortly before showing symptoms of the potentially fatal illness. The case of legionnaires’ prompted an investigation by health chiefs.

But the IAH said last night that levels of Legionella contamination had been classed as “so low that the HSE require no further action”.

Meanwhile, open countryside and footpaths at the centre of the FMD outbreak were closed to the public last night. Entry into common land in the Elstead Protection Zone has been prohibited after Surrey County Council received consent from the Secretary of State.

— Two freelance photographers have been charged under the Animal Health Act after allegedly breaching a cordon on Saturday close to land where FMD had been identified. Philip Hollis, 44, from Kingston upon Thames, and James Purkiss, 37, from Swindon, will appear at South West Surrey Magistrates’ Court in Guildford today. Police and Trading Standards officials announced the charges yesterday but praised the majority of the media for performing “an absolutely vital role” in informing people about the outbreak.

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