An FSA spokesman said there was no evidence any contaminated chickens had entered the UK but it was maintaining a watching brief after last week confirming eggs contaminated through the alert had been used to make cakes and quiches sold in UK supermarkets.
The first confirmation of tainted meat came after the discovery that farm animals in Germany had eaten contaminated feed, possibly for months. Three chickens – out of 15 samples of chicken, turkey and pork sent to the EU Commission – showed a dioxin concentration twice as high as legally allowed.
An agriculture ministry official in Germany said the chicken meat had not been sold but eating it would not have been harmful in the short term since the contamination levels were so low.
Dioxins are contaminants that often result from industrial combustion, and exposure to them at high levels is linked to an increased incidence of cancer.
Germany has frozen sales of poultry, pork and eggs from more than 4,700 farms to stem the spread of food that could have been contaminated.
The contamination appears to have occurred after oils intended for biofuel became mixed with oil destined for animal feed which was sent to 1,000 pig and poultry farms in the country.
European chiefs confirmed on Friday that some of eggs that were contaminated were subsequently processed in Holland, where they were mixed with non-contaminated egg to make liquid egg which was distributed to the UK to firms who produce a range of products for British stores. Supermarkets Tesco, Morrison's, Asda, and Sainsbury's later removed affected cakes from their shelves.
The FSA said the supermarkets had already sold most of the affected food, which had a short shelf life, but added the risks to humans were minimal.
A spokesman said: "At the moment there is no evidence that any other product other than liquid egg has been supplied to the UK. If there are any further updates, we will keep the public informed."