Beijing: Chinese authorities said Wednesday they were investigating how eggs came to be contaminated with the same industrial chemical at the centre of a milk scandal that sickened thousands of babies, as more tainted eggs turned up in Hong Kong and the mainland.

The action follows a brand of chicken eggs produced by China's leading egg processor Dalian Hanwei Enterprise Group being pulled from some stores in the country after Hong Kong food safety regulators found excessive levels of melamine in eggs from the company.

The widening food scare has exposed the inability of Chinese authorities to keep the food production process clean of melamine, the chemical that sparked the recent dairy crisis, despite official vows to raise food safety standards.


Hanwei's Web site said that besides the domestic and Hong Kong markets, its egg products are exported to Japan and countries in Southeast Asia.

China's fresh eggs are mainly exported to the Chinese territories of Hong Kong and Macau, while processed egg products are also sold to Japan and the U.S., according to a February egg market report on the Agriculture Ministry's Web site, the latest available report.

The government of Dalian, the northeastern port city where Hanwei is based, said in a notice dated Wednesday that it was first alerted to the problem of melamine-tainted eggs more than a month ago — but it did not explain the apparent delay in publicly reporting the problem.

The city government said it immediately ordered Hanwei to recall the eggs deemed "problematic" and temporarily halt its egg exports. By October 5, seven shipping containers that had reached Hong Kong carrying Hanwei's eggs had been recalled, while two other containers that stayed in Hong Kong were sealed off.

The recalled eggs were destroyed to prevent them from entering the domestic market, the notice said, while further tests on other batches of eggs from the company did not detect melamine.

It was unclear how the chemical got into eggs. But a Chinese agriculture official, Wang Zhicai, was quoted by the Beijing News newspaper Tuesday saying it was highly likely that melamine had been added to the feed given to the chickens that laid the eggs. Melamine is not an animal feed additive and is banned from being mixed in, Wang said