The Department for the Environment, Food and Rural Affairs (簡稱Defra。BBC翻譯為「英國環境、食物及鄉村事物(sic 務)部」；日本翻譯為「英国の環境・食糧・農村省」 )
科學家周六晚取得突破，發現這次的口蹄疫病毒並非一般動物身上能出現的，而是來自疫苗，而且從來沒有在歐洲國家出現過。 該發現讓當局追查到這次的口蹄疫情來自一家私營製藥公司，它距離事發農場不到三英里。這家名為Merial Animal Health的公司與一個政府實驗室共享部分設備，前者同時獲得歐盟授權生產給動物用的疫苗（存放了5000劑口蹄疫病毒疫苗）。當局正在調查該製藥公司上個月是否出現失誤，從而洩漏出大批口蹄疫病毒。
The protection zone in Surrey has been extended
The strain of the disease found is identical to that used for vaccines and testing at a Pirbright research site.
The head of the Institute for Animal Health, which is based there, said there had been no biosecurity breaches.
Environment Secretary Hilary Benn has urged people to remain vigilant as the source has not been confirmed.
As well as the Pirbright Laboratory, a research facility of the government's Institute for Animal Health (IAH), the site houses the private pharmaceutical company Merial Animal Health.
The strain of the disease identified at Wolford farm, near Guildford, was used in a batch of vaccine manufactured on 16 July by Merial.
Mr Benn said that safety inspectors would first examine the Merial part of the site, "because we know that vaccines were being produced last month using the particular strain".
David Biland, Managing Director of Merial in the UK, said: "Merial will co-operate fully with the UK government to determine the source of the disease, and will fully support Defra scientists in bringing this outbreak to a speedy and satisfactory conclusion."
In a statement, IAH director Professor Martin Shirley said there had also been limited use of the strain at the institute within the past four weeks.
He said: "The Institute for Animal Health operates under strict biosecurity procedures licensed by Defra.
"In addition to our general checks on biosecurity, operation of equipment, procedures and physical barriers - which have shown no breaches of our procedures - we have been able to check our records specifically for use of this strain."
He said he welcomed the independent review into procedures at the Pirbright site.
Mr Benn said as well as the health and safety inspection, an urgent review of biosecurity would be carried out.
"The HSE's job will be to look and see whether everybody at the site has done what they're legally required to do to protect anyone from the consequences of the work that they rightly do there."
He also commended the authorities for their swift reaction to the outbreak at the farm, three miles from the Pirbright site.
Mr Benn told BBC News 24 Sunday the link to the site was a "promising lead", but he added: "We don't know for sure, and therefore it's very important that people continue to be vigilant."
There had been reports of possible foot-and-mouth infection at four other farms, but these had all tested negative for the disease, he said.
The Department for the Environment, Food and Rural Affairs (Defra) has increased the size of the protection and surveillance zones covering farms in the area to 10km.
The strain of foot-and-mouth identified is not one normally found in animals but is used in vaccine production and in diagnostic laboratories.
In a statement, Defra said: "The present indications are that this strain is a 01 BFS67-like virus, isolated in the 1967 foot-and-mouth disease outbreak in Great Britain."
Merial voluntarily halted vaccine production as a precaution.
BBC science correspondent David Shukman said that if the virus did escape from the Pirbright laboratory, the question to ask was how.
He said: "Like the manufacture of any vaccine to defend against a virus, this one used samples of live virus in the production process.
"Experts speculate that either it escaped through the ventilation or possibly an employee carried it out accidentally on a boot or clothing."
Microbiology expert Hugh Pennington said that if the source was identified as the Pirbright complex it could be welcome news.
He said: "If we know exactly where the virus has come from, and particularly if it's a vaccine type of virus, it's less likely to be a nasty virus."
The review of biosecurity measures at Pirbright will be led by Professor Brian Spratt of Imperial University, who will report back to Mr Benn.
Mr Benn also commended Chief Veterinary Officer Debby Reynolds for the swift response to the outbreak.
A revised 3km protection zone now encompasses both the infected farm premises and the Pirbright site, with the surveillance zone extending to a 10km radius.
A ban on the movement of all livestock is in place in England, Scotland and Wales after infected cattle were culled at the Surrey farm.
Northern Ireland has imposed a ban on all cattle, sheep and pigs from Britain, but there are currently no restrictions on the movement of livestock within NI and across the border.
Britain has also imposed a voluntary ban on exports of all animals and animal products, Defra said, and the European Commission said it would ban live animal exports from the UK, as well as meat and dairy products from the area affected by the outbreak.
Mr Benn said: "The lessons of foot-and-mouth in 2001 were in essence that you had to act quickly, you needed to have systems and you needed to follow the science. And that's exactly what we've done."
He pointed to the fact that a ban on animal movements was imposed in about three hours on Friday, as opposed to the three days it took in 2001.
There is also an 8km air exclusion zone around the site.
Some 64 cattle have since been culled at the infected farm, and there has been a cull of one other herd of cattle adjacent to the farm as a precautionary measure.
The outbreak in 2001 led to between 6.5 million and 10 million animals being destroyed and cost as much as £8.5bn.
Defra has set up a helpline in response to the latest outbreak on 08459 335577.