Britain's Food Standards Agency is investigating whether meat contaminated with bird flu had reached shops.
The alarm was raised after the government concluded yesterday that a bird flu outbreak at a giant turkey farm was probably caused not by wild birds but by contaminated shipments from Hungary, possibly of processed turkey meat.
"If it was found that (infected) meat had got into the food chain it would be illegal and we would take appropriate action," a Food Standards Agency spokeswoman said.
"I couldn't tell you what we would do. But we wouldn't want that meat there. At the moment we are not in the process of withdrawing any turkey products from supermarket shelves."
She added: "If infected meat had got into the food chain it wouldn't be a safety risk to consumers."
Bernard Matthews, Europe's largest turkey producer which has had 160,000 birds destroyed after an outbreak in Britain, has acknowledged shipping 38 tonnes of partially processed turkey meat from Hungary per week.
The firm suspended shipments from Hungary after the British government concluded yesterday that the virus which caused the British outbreak was identical to one that caused an outbreak in Hungary in January.
Commercial Director Bart Dalla Mura said none of the turkey his company had imported was from the areas in Hungary that were declared off limits during the outbreak there.
"The material we imported - we made all our checks - came from nowhere near the restricted region," he told BBC radio.
"There had been no influenza in (Hungarian) turkey, there's no restrictions on bringing turkey from Hungary and our paperwork is absolutely secure that says that was the case."
Officials initially said they believed the virus was brought to Britain by wild birds and was unlikely to have been linked to the Hungarian outbreak weeks earlier. But they changed their minds on Thursday, saying they now believe the strain found in Britain was identical to that found in Hungary.
The virus may have been brought to Britain from Hungary in turkey meat, or by contaminated vehicles, Britain's deputy chief veterinarian Fred Landeg told BBC radio.
"The virus has got here somehow. We are focusing our investigation ... on possible movements of poultry meat and vehicles from Hungary, and possibly personnel," he said. "There is quite a lot of movement of poultry and poultry products within Europe. Those are legitimate and legal movements."