Six cattle have been slaughtered after bluetongue type one (BTv1) was confirmed in cattle imported from France to a farm in Lancashire.
The disease was discovered in five of nine Bazadaise suckler cattle imported by Andrew McCulloch of Hambleton, Poulton-le-Fylde. Tests on one other cow were inconclusive.
NSA chief executive Peter Morris told Farmers Weekly that the cattle, from an area of France currently battling strains one and eight, had been moved legally.
The cattle had been vaccinated against bluetongue strains one and eight 60 days before travelling to the UK.
However the cattle appear to have been infected with BTv1 around the same time as they were vaccinated and showed low level viremia when post-imported tested by DEFRA.
Mr Morris said DEFRA had suggested there was a relatively low risk of onward transmission to UK midges and other stock as the affected cattle had been culled on detection of the disease.
It is also understood the virus was present only at low levels.
The NFU called for a suspension of imports from bluetongue-susceptible areas following the discovery of the disease.
NFU president Peter Kendall said a lack of vaccine for BTv1 meant it was vital the disease was kept out of the UK.
“In light of the uncertainty and the enormous risk to our industry it is only right that we do all that we can to protect our livestock sector and at the moment I believe that this means that we should suspend imports from BTv areas,” he said.
“I am sure that no farmer wants to import BTv1 into the country and therefore until we are confident that the controls on moving animals from BTv areas, as set out in the EU regulations, are working effectively to protect our livestock then we should suspend imports from these areas.”
DEFRA secretary Hilary Benn is expected to make a statement on the outbreak later.