Ministers last night defended their decision to allow imports of turkeys from Hungary after the outbreak of avian flu at Bernard Matthews' farm in Suffolk.

Ministers last night defended their decision to allow imports of turkeys from Hungary after the outbreak of avian flu at Bernard Matthews' farm in Suffolk.

It was all quiet yesterday at the site at Holton, near Halesworth, where the deadly H5N1 strain was confirmed on February 2 - as the threat of turkey products being pulled off supermarket shelves by the Food Standards Agency (FSA) remained.

Environment secretary David Miliband insisted an import ban would have breached European Union rules and invited continent-wide retaliation against UK farmers.

He said it was clear there had been a “serious bio-security lapse” leading to the infection of turkeys at the Matthews plant, and he would have been ready to impose a ban if vets told him it was necessary for public health.

But he added: “There are two reasons we didn't do that. First of all, the vets didn't say that for public health reasons that was a sensible thing to do.

“And secondly, there will be poultry farmers around Britain saying 'Hang on, if there's an outbreak in Suffolk, why should I be penalised outside that area?'

“To have invited the sort of retaliation from around Europe and elsewhere for all of the British poultry industry would not have been a sensible thing to do.

“What we have done, rightly, is to follow the scientific advice and ensure that EU rules are rigorously implemented.”

But John Oxford, a virology expert at Bart's Hospital, London, said he was “bemused” by the handling of the outbreak.

He said: “I wouldn't have thought they would allow the import of turkey pieces from a country - that is, Hungary - where they have already had an outbreak of H5N1. I'm surprised they have allowed it. This is a £3bn industry. You would want to put all the things in to protect your own set-up, and that would have been one of them, I would have thought.”

Links between the Matthews' Holton site and its Hungarian operation were played down in the days immediately following the Defra announcement that thousands of birds had already been killed by the disease.

Yesterday a national newspaper revealed Defra allowed Bernard Matthews to continue importing dead turkeys from Hungary after geese in the south of the country fell victim to avian flu. A consignment of 20 tonnes of turkey meat was alleged to have been imported as late as three days after bird flu was confirmed at the Suffolk plant.

The claims came the day after the National Farmers Union, including representatives in Norfolk, called for all poultry imports from countries with bird flu to stop until the cause of the Holton outbreak was established.

Animal welfare minister Ben Bradshaw made clear yesterday that the company could face prosecution if it were shown to have broken the law.

Theories suggesting that the virus had arrived in the UK via wild birds have now been largely dismissed.

Paul Hunter, UEA professor of health production, said: “The reason the FSA will not rule out a product recall has nothing to do with risk to human health. The major reason for recalling products would be to prevent the virus re-entering the bird population.”

He added: “My advice is to practise good hygiene in the kitchen when preparing poultry. This includes washing your hands before and after handling meat and not rinsing poultry under the tap.”

Reports on sales produced varying results at the weekend, with Tesco announcing only a slight fall in sales, Asda claiming the outbreak was having no impact on customers and Sainsbury's revealing a 10pc drop across its poultry products.

Bernard Matthews has insisted its food is completely safe and that there is no risk of catching flu.