Frederic Vincent, spokesman for European Health Commissioner John Dalli, said British authorities were tracing a consignment of food pending checks on whether it is toxic.
Britain was informed Wednesday that the suspect food had been exported there, he added, as the search for the eggs that began on December 28 in Germany widens.
The announcement came as it was revealed the German firm behind the contamination said it had received death threats.
Also on Thursday, Bavaria became the ninth German state ensnared by the dioxin animal feed scandal. About 410,000 eggs have been supplied to the southern state from contaminated batches in Lower Saxony. A least some of the eggs had already been sold to processed food companies.
The scandal has continued to spread across Germany since it emerged that about 3,000 tonnes of industrial fatty acids contaminated with the highly toxic substance dioxin were used to enrich feed for egg-laying hens, poultry and pigs.
So far, the states of Lower Saxony, Schleswig-Holstein, Hamburg, North Rhine-Westphalia, Saxony, Saxony-Anhalt, Thuringia and Brandenburg are known to be affected. Bavaria now joins them.
As only a small quantity of oil is generally added to animal feed, the original 3,000 tonnes may have been mixed into tens of thousands of tonnes of feed.
News that the problem continue to widen came as calls grew for severe penalties for the firm behind the contamination and tighter regulations for the feed industry. The dioxin-contaminated substances were mixed into feed by animal feed firm, Harles & Jentzsch, based in Uetersen in Schleswig-Holstein.
The firm's boss, Siegfried Sievert, who acknowledged the firm had been “careless,” has received death threats, along with three of his workers. Sievert told daily Westfalen-Blatt the police had been informed of the threats, which came by phone and email.
The European Commission did not know whether the foodstuff had been used in products such as mayonnaise and cake powders, or put into shampoo.
It said however that even if the eggs were found to be tainted the contamination would "be weak" and the mix with other eggs "would have diluted it".
Consumer Minister Ilse Aigner announced there would be severe consequences for the firm behind the scandal.
“Anyone who puts the existence of hundreds of firms at risk and endangers the health of consumers must be held accountable,” Aigner, of the Christian Social Union party, told the Hannoversche Allgemeine Zeitung
Lower Saxony state premier David McAllister of the Christian Democratic Union, also called for tough sanctions.
“Those responsible must be held to account,” he told the Nordwest-Zeitung.
Environmentalist Greens MP and farmer Friedrich Ostendorff said: “Without new laws, we will not get a grip on the animal feed industry. We need a precise set of rules about what may go into animal feed.”
Harles & Jentzsch was certified for quality and safety by the monitoring firm Dekra on October 18 last year. However Dekra's press office told the Passauer Neue Presse that their evaluation did not actually involve testing of feed and that this was in line with protocols.
“The Dekra Certification company did not assess or analyze any products within the certification framework and also, in accordance with the quality and safety requirements, carried out no analysis.”
They declined to comment on how dioxin got into the feed.
The German Farmers' Federation (DBV) has called for farmers to be compensated and for changes to be made to food and animal feed legislation.
The DBV also said there was no threat to consumers.
“The initial results show that, with the exception of some firms in North Rhine-Westphalia, they lie well below the acceptable limit,” DBV boss Helmut Born told the Berliner Zeitung.
“Losses for farmers who have to cull their chickens and destroy their eggs will have to be compensated for by those causing this damage.”