British officials said on Thursday that the foot and mouth virus may have leaked at the same laboratory that generated an outbreak earlier this year.

The Merial Animal Health facility at Pirbright in Surrey, southeast England was at the center of a foot and mouth outbreak in August that led to the mass slaughter of more than 6 million farm animals. While the outbreak was contained within a relatively small area, it cost around $17.55 billion. The European Union temporarily banned all exports of animals, meat and milk from Britain, until the outbreak was contained.

An investigation conducted at the time highlighted breaches in biosecurity and a malfunction of the drainage system at the research site.

Environment Minister Hilary Benn said Thursday that officials at the Merial facility believed a possible leak of the live virus may have occurred again, into a contained drainage system.

Merial discovered Monday that a faulty valve was causing the leak; operations at the facility stopped immediately. The faulty valve was replaced on Tuesday, reports the Times Online.

Merial informed the Department for Environment, Food and Rural Affairs about the incident on Tuesday; the company's operating license was suspended again, as happened in August.

“Merial judged that the valve had been leaking, allowing an unintended probable release of live foot and mouth disease virus into the contained drainage system, which was then pumped to the final chemical treatment facility without being heat-treated,” Benn said in a statement.

Officials emphasized that the virus had not been released into the environment.

“The site's bio-security waste treatment facilities handled the situation exactly as they are designed to do,” the company said. “We expect to be operational again soon.”

Britain's Department for Environment, Food and Rural Affairs (Defra) said it had suspended Merial's licence allowing the use of foot and mouth and bluetongue viruses for vaccine production, reports the Times Online.

Merial, a private joint venture between Merck & Co. and Sanofi-Aventis, produces pharmaceutical products and vaccines for animals. Merial employs approximately 5,000 people and operates in more than 150 countries worldwide, according to its website. Its 2006 sales were nearly $2.2 billion.

Britain's National Farmers Union (NFU) said in a statement: “It's extremely concerning that part of the system at Merial has failed. However, we have been reassured by Defra that the secondary decontamination systems have worked effectively and that no live virus has escaped into the environment.”

The union added that the rapid containment of the live virus was a relief: “To say we're relieved we don't have another foot and mouth disease virus problem is a huge understatement.”