Thousands of ducks and a million duck eggs have been destroyed after the toxic chemical dioxin was found in eggs at a supermarket, the government said yesterday.
There have been no reports of illness linked to the chemical.
Experts were looking for the source of the toxin, found in February in salted duck eggs for sale at a supermarket in Changhua County, the Council of Agriculture said in a statement.
The council said it did not publicize the finding earlier because it wanted to avoid creating a panic.
Investigators have found that the eggs originated from six farms in the area, the council said.
Since March, 20,000 ducks have been slaughtered and about a million eggs have been destroyed, it said.
The Council of Agriculture has been unable to find the cause of the poisoning. The government has asked experts from the National Cheng Kung University in the southern city of Tainan to investigate.
The experts have excluded animal feed as a possible source of the poisoning, the council said.
Dioxin is a toxic chemical that persists in the environment and is believed to cause cancer and birth defects.
The substance is a byproduct of the manufacture or burning of plastics and chemicals.