BERLIN • Discount supermarket giant Aldi said it was pulling all Dutch eggs from its shelves in Germany over an insecticide scandal that has spread to food stores across Europe.

Aldi said on Friday that it was making the move "purely as a precaution", but acknowledged it could lead to "market shortages" for eggs.

The authorities in Belgium, Switzerland and Sweden also said they were tracking shipments and removing eggs, as the impact of the affair widened.

Aldi took action after it emerged that at least three million eggs tainted with a toxic insecticide had entered Germany and been sold. However a regional agriculture minister, Mr Christian Meyer, told ZDF public TV it was now believed that 10 million contaminated eggs might have reached the country .

The authorities suspect the substance, fipronil, was introduced to poultry farms by a Dutch business named Chickfriend that was brought in to treat red lice, a nasty parasite in chickens.

In large quantities, the insecticide is considered "moderately hazardous", according to the World Health Organisation, and can be dangerous to people's kidneys, liver and thyroid glands.

Eggs were also withdrawn by supermarkets in Switzerland, but the authorities who approved the recall urged people not to panic. The European Commission is following the case very closely as issues of public health are at stake, said spokesman Anna-Kaisa Itkonen.

With losses set to run into millions of euros, it is another blow for Dutch poultry farmers after 190,000 ducks were culled last November amid a highly infectious strain of bird flu.

Germany said Belgium and the Netherlands, which have launched criminal investigations into the matter, were obliged to shed light on the scandal.

AGENCE FRANCE-PRESSE