Last month's outbreak of foot and mouth disease in Surrey could have been caused by a damaged pipe at the animal research site close to the affected farms.

A report by the Health and Safety Executive is expected to reveal that traces of the disease were found in a pipe running between the government's Institute of Animal Health and a private pharmaceutical company called Merial, which are both based on the site in Pirbright, near Guildford.

According to reports, floodwaters could have carried the virus to the surface, which was then inadvertently spread off-site by builders working at the complex.