The FSA said two slaughtermen had had their licences withdrawn, and it was looking at the footage in more detail.

BBC: Nantwich horse abattoir investigation after secret film

Now the concentrated effort against the disease is inside the extended blue restriction zone - some 500 square miles of the North East - where vets, slaughtermen and soldiers operate the most stringent bio-security regime around a sweeping slaughter and culling campaign.

BBC: Disease 'stranglehold' on farmers