Supermarket giant Aldi has withdrawn all eggs from sale from its stores in Germany as they may have been contaminated by insecticide.
Tests showed that the chemical fipronil, which can harm people's kidneys, liver and thyroid glands, was found in eggs from the Netherlands.
Fipronil is used to treat lice and ticks in chickens.
One German official said up to 10 million of the contaminated eggs may have been sold in Germany.
Christian Meyer, the agriculture minister for Lower Saxony, told German television that there was a risk to children if they ate two of the eggs a day.