As concern mounted throughout Europe over Belgian chickens and eggs produced on farms whose feed was contaminated with dioxins, the Ministry of Agriculture asked retail organisations and food producers to check their inventories for potentially suspect food.
Chicken and egg products made in Belgium since early January are implicated in the latest continental food scare, following another over French cheese.
Although most Belgian chocolate is not affected, some filled chocolates are. Neuhaus, one of Belgium's most prominent chocolatiers, yesterday took one of its chocolate products off display in Brussels.
In Britain the supermarket chain Asda said yesterday that it had cleared three own-brand pre-packed meats - its garlic and herb chicken, Belgian chargrilled chicken and honey roast chicken - at the weekend as a "purely precautionary measure" following checks.
A spokesman said: "If we can ascertain there is no link with the Belgian situation they will go back on sale. With regards to the other products such as chocolate, checks are under way."
Tesco and Sainsbury said that they were not aware of any Belgian products that were made from chickens or eggs.
Yesterday Franz Fischler, the European Union's Agriculture Commissioner, said that Britain had not imported any contaminated chickens.
The European Commission has ordered all European countries to trace and destroy poultry or egg products which could be contaminated by the cancer- causing dioxin which poisoned animal feed.
Emma Bonino, European Commissioner for Consumer Affairs, did not play down the danger posed by contaminated matter passing into the food chain. Doses which have been discovered "are sufficient to give rise to concerns", she said.
She added: "Acute effects for the consumer appear to be relatively unlikely. There are possible long-term effects. Dioxin is in category one of carcinogens. It is impossible to assess the effects because we do not know the rate of exposure."
France's Farm Minister, Jean Glavany, described the scandal, over which two Belgian ministers resigned, as a "grave crisis". In France, 70 poultry farms have been quarantined.
n A batch of home-made cheese could be at the centre of an E.coli outbreak which has put seven children in hospital in the north-east of Scotland, health officials said last night.
Grampian Health Board said the cheese, part of a one-off batch not available commercially, was one of several possible sources of the infection.Reuse content