A government institute and private firm occupy the Pirbright site
The latest case of foot-and-mouth, at Egham, Surrey, involves the same strain of the disease that infected herds last month.
Official reports blamed the previous outbreak on the Pirbright laboratory site, 10 miles away.
The Pirbright facility, near Guildford, is shared by two occupants - the government's Institute for Animal Health (IAH) and Merial Animal Health.
The IAH research facility is a world reference laboratory for foot-and-mouth, which tests and catalogues strains of the disease from all over the world.
Private pharmaceutical company Merial Animal Health is an international animal healthcare company that makes vaccines.
Merial is a joint venture between two parent companies - Merck, a major US-based drug firm, and the French company Sanofi-Aventis.
Last year, it produced 100 million vials of animal vaccine in 15 manufacturing sites around the world.
Merial also produces a range of other pharmaceutical products for livestock, pets and wildlife. Last year, sales of its products topped £2.2bn worldwide.
A government review of the Institute for Animal Health five years ago found deficiencies in the standard of some of its laboratories.
The review, for the Biological and Biotechnology Research Council, said the institute "was not commensurate with what might be expected for work with infectious diseases".
And the review authors said they were concerned that some areas were "shabby".
Questions were also raised about the loss of key skills at the laboratory as senior personnel left and were not replaced.
The head of the laboratory, Professor Martin Shirley, said since the report good progress was being made on a £121m development programme which included building new laboratories by 2011.
He added that planning to cope with senior staff leaving was being continually appraised.
Earlier this year, Prof Shirley told MPs he was trying to run a Rolls-Royce service, but was being "funded at the level of a Ford Cortina".
As well as foot-and-mouth, the institute also focuses on diseases in cattle, sheep, horses and pigs, including lumpy skin disease, rinderpest, African swine fever, swine vesicular disease and equine encephalosis.
The institute's findings are supplied to Defra, the Department of Health and the Department for International Development.
The institute, which has two other sites - in Compton, Berkshire, and the Neuropathogenesis Unit, in Edinburgh - also carries out work for the European Union.
The strain involved in the outbreaks is not one that has previously recently been found in animals, but is similar to those used in diagnostic laboratories and vaccine production.
There were two reports released earlier this month into the initial outbreak, one by the Health and Safety Executive (HSE) and the other by Professor Brian Spratt of Imperial College.
They concluded it was probably caused by leaking drains, heavy rain and building work.
The HSE said it was not clear which of the two labs at Pirbright was responsible.
The reports included evidence of damage to pipes with tree roots breaking through, and unsealed manhole covers.
The inquiry suggested that affected soil could have been taken to surrounding farming areas on the wheels of vehicles that visited Pirbright.
The investigators said there had been dispute between Merial and the IAH over who was responsible for maintaining the drains.
Following the reports, Environment Secretary Hilary Benn said there was no excuse for the outbreak.
He said: "What these reports do show is that the most likely explanation for this outbreak is a unique and unhappy combination of circumstances.
"The weaknesses in the drains, the heavy rain and floods, the building work taking place on the site, and the movement of vehicles."
He added: "It should not have happened, even in these extraordinary circumstances and it must not happen again."