Supermarkets have denied there has been a slump in poultry sales after the outbreak of bird flu at a Bernard Matthews turkey farm in Suffolk.
A cull of 160,000 birds was carried out in Suffolk last week
Tesco and Asda said they were not seeing any significant drop in sales despite news of an investigation into whether infected meat is on shelves.
The farmers' union has called for more controls on foreign meat imports after the outbreak was linked to Hungary.
Experts stress there is no danger to humans if meat is properly cooked.
Tesco said on Saturday its position was unchanged from last weekend, when it saw a slight drop in poultry sales.
A supermarket spokesman said there had also been a fall in sales of Bernard Matthews products but would give no more details.
A spokeswoman for Asda said there had been "absolutely no impact" on poultry sales in its stores.
Sainsbury's said it had seen a marked drop of 10% across all its poultry products but a spokeswoman said bad weather could have affected sales.
The Food Standards Agency is investigating whether turkey products in supermarkets could be infected.
1 Feb: Vets called to Bernard Matthews farm in Suffolk after turkeys die
3 Feb: Vets confirm H5N1 strain
5 Feb: Environment minister says most likely cause is from wild bird, but other possibilities being investigated
8 Feb: Government vet suggests turkey meat from Hungary may be to blame. Bernard Matthews denies link
9 Feb: FSA examines whether infected meat may have entered food chain
The government's chief scientist, Professor Sir David King, warned that meat may have to be withdrawn from shops to stop the disease spreading to other animals.
Paul Hunter, professor of health production at the University of East Anglia, said this could happen if wild birds ate infected meat.
"The major reason for recalling products would be to prevent the virus re-entering the bird population," he said.
"If a contaminated product was discarded and eaten by birds there is the potential for this to cause a further outbreak."
Richard MacDonald, of the National Farmers' Union, said the outbreak at the Bernard Matthews plant in Holton "posed questions about import controls".
He said he had asked the Department for Environment, Food and Rural Affairs "to examine very carefully what they do in terms of import controls and whether or not we should be continuing with this sort of practice".
Hungarian officials said there was no evidence to prove that infected poultry from Hungary, which saw a bird flu outbreak last month, caused the UK outbreak.
Questions are being asked of Bernard Matthews, which owns a site in Hungary, after it emerged the firm had been shipping partly processed meat from the country into the UK.
FSA COOKING ADVICE
After cooking a whole bird, pierce the thickest part of the leg with a clean knife or skewer. The juices should run clear
The juices should not have any pink or red in them and there should be no pink meat
People are advised not to eat raw eggs or use raw eggs in dishes that will not be cooked
Eggs should be cooked until the whites are solid
Bart Dalla Mura, commercial director of Bernard Matthews, said the firm had not brought in any poultry or meat products from inside the infected region of Hungary.
"We have made all our checks and they have come from nowhere near the restricted region. That is what our paperwork says to us," he said.
Earlier this week, a cull of almost 160,000 turkeys at the Bernard Matthews plant was completed, after the discovery of the H5N1 virus.
The H5N1 virus does not pose a large-scale threat to humans, as it cannot pass easily from one person to another.
But experts fear the virus could mutate at some point in the future and trigger a flu pandemic, potentially putting millions of human lives at risk.