The poultry sector has said there will not be any fipronil found in the chicken meat as the birds do not live long enough for lice to be an issue.

Millions of eggs have been recalled from shops and warehouses in Belgium, the Netherlands and Germany in recent weeks due to fears of contamination.

On Monday the European Commission and the UK’s Food Standards Agency (FSA) said that they had discovered over the weekend that around 20,000 potentially contaminated eggs had also been imported into the UK. Officials in France, Sweden and Switzerland have also been informed of a risk to consumers.

The FSA said the number of eggs involved represented about 0.0001% of the eggs imported into the UK each year and that there was no need for consumers to be concerned.

According to the World Health Organisation (WHO), fipronil can damage the liver, thyroid glands and kidneys if ingested in large amounts over time.

Tjitte Mastenbroek, a spokesman for the Dutch food safety agency, the NVWA, said: “We are currently testing chicken meat in the poultry farms wher eggs were infected to determine whether the meat is contaminated as well.”

If no insecticide is found in the meat, the farms will be cleared to resume sales, Mastenbroek said, calling the tests “a precautionary measure”. The investigations are said to be focusing on “a few dozen” farms that produce both eggs and chicken meat.

Germany’s agriculture minister, Christian Schmidt, said that the contamination of millions of eggs with a potentially harmful insecticide was “criminal”.

Prosecutors in Belgium and the Netherlands have launched investigations, with the focus being on a Dutch retailer of the anti-lice substance, and its Belgian supplier.

Questions have been raised as to how long the Belgian food safety authorities knew of the contamination before they alerted the European Commission.