Employees at the laboratories near the site of the foot-and-mouth outbreak are being questioned “urgently” as a government report concluded that a deliberate or accidental transmission of the virus by a person at one of the sites was one of the most likely causes of the outbreak.

The preliminary report from the Health & Safety Executive confirmed the “strong probability” that either the laboratory owned by Merial, an animal health company, or the laboratory owned by the Institute of Animal Health, at the same site in Pirbright, was the source of the outbreak.