A new government-commissioned inquiry will highlight the possibility that 120 construction workers working at the Pirbright Laboratory site in Surrey were responsible for transporting the disease four miles to the two farms at the epicenter of the outbreak.

Pirbright is used to investigate diseases of farm animals, and contained a similar strain of the virus to that found on the infected livestock. The builders were carrying out work designed to prevent such outbreaks as these, but they were not subject to the stringent cleansing practices as more permanent staff.

The report also warns that, despite these suspicions, the exact cause of the outbreak may never be decided upon.

The remaining sanctions following the outbreak are due to be removed this Saturday, when the 10km ‘surveillance zone’ in Surrey and restrictions on moving livestock will both be lifted. Following no further outbreaks, the UK should regain internationally-recognised FMD-free status on 7 November, three months after the last case.

Gordon Brown met farmers’ leaders yesterday to discuss the report, and is expected to publish it on Friday.

For further information, visit the Department for Environment, Food and Rural Affairs (Defra) website, or call the FMD helpline, on 08459 335 577.