Eggs from 44 farms in Taiwan were found with excessive levels of fipronil, a pesticide considered poisonous by the World Health Organisation, the island's agricultural authority said Saturday.

As of Saturday noon, the bureau had tested all egg samples collected from 354 farms across Taiwan.

A total of 64,570 kilograms of eggs, or more than one million eggs, with excessive fipronil were barred from leaving their farms or being removed from stores, according to the agricultural authority.

All 44 farms were asked to take strict controls to prohibit eggs from leaving their premises. The prohibition will not be lifted until the eggs meet the standard in a re-examination, the bureau said.

The agricultural authority launched an inspection of chicken farms across the island since 20 August by collecting and testing samples amid fears of fipronil in the local egg market.

On 22 August, eggs laid at three farms in Changhua were found with excessive levels of the pesticide.

Fipronil is a pesticide effective on a large number of pests and its use is forbidden on animals to prevent liver, thyroid and kidney damage.