Normandy, England ? Britain’s health and safety agency said Tuesday there was a strong probability that a foot-and-mouth outbreak in southern England originated at a vaccine lab and was spread by human movement.

The outbreak was discovered on a farm just four miles from the Pirbright vaccine laboratory, which is shared by the government’s Institute for Animal Health, or IAH, and a private pharmaceutical company, Merial Animal Health, the British arm of Duluth, Ga.-based Merial Ltd.

There is a “real possibility” the disease was spread by human movement, and the possibility it was transmitted by air or floodwaters was “negligible,” the government’s Health and Safety Executive said in the report.

Environment Secretary Hilary Benn said the report brought efforts to stop the disease “a bit further forward.” He said the possibility that the strain had been released by human movement would be urgently investigated, and that footpaths in the protection zone covering two infected farms would be closed immediately.