The World Health Organisation has asked China to explain why a poisonous industrial chemical was found in eggs there.

China correspondent, Stephen McDonell reports supermarket chain Wal-Mart has started removing some brands of Chinese eggs from the shelf, after the industrial chemical, melamine, was found in eggs sold in Hong Kong.

There are concerns here that the harmful chemical might have contaminated a wide number of food and animals, rather than just dairy products.

Four Chinese babies have died from kidney failure after drinking infant milk formula containing Melamine.

Now the World Health Organisation's regional food safety adviser has asked the Chinese government for information about the quality of eggs and feed given to chickens.