A pre-emptive slaughter of animals has been ordered and a national movement ban has been put in to place.
The surveillance zone around the original outbreak was only lifted at midday on Saturday.
Peter Kendall, president of the National Farmers’ Union, told BBC News 24 it was a “disaster” for British agriculture and the industry “will be devastated”.
Prime Minister Gordon Brown is due to chair a meeting of the Cobra emergency committee anytime soon.
A 10km control zone, centred on the affected farm near Egham, has been put in place and cattle from the affected herd are being culled.
Further updates as we get them.