Maruha has received hundreds of thousands of calls about the problem.

"The products will have a strong smell and eating them may cause vomiting and stomach pain," it said in the notice, which included 51 colour photos of the problem products.

The health ministry said it had confirmed 556 people suffering such symptoms after eating those products up to Tuesday night. In a notice on its website, it ordered Maruha Nichiro to recall all potentially affected products and to be forthright in informing the public about the situation.

Estimates of the number of people affected vary. Kyodo News agency said yesterday that its tally found 909 people were ill after eating the Maruha products. Earlier, public broadcaster NHK said information from local governments showed 356 people affected.

Both reports said it was unclear if consumption of the tainted products was directly responsible for the illnesses, suggesting possible public hysteria.

The health ministry said it had not detected malathion in nearly three dozen cases tested.

Tokyo-based Maruha Nichiro says it has retrieved about 1.1 million packages subject to the recall so far.

Last week, it issued a formal apology and appealed to consumers not to eat any of the affected products.

Police are investigating how the items were contaminated with malathion, reportedly by up to 2.6 million times the allowable limit.

Malathion is a pesticide used in farms and gardens and to kill fleas on animals and people.

At high enough concentrations, it can cause death, according to the United States Centres for Disease Control.

There have been no reports of life-threatening illnesses from Maruha's products, but the contamination has deepened public fears, undermined by numerous food quality scandals.

Late last year several top hotels and department stores apologised after it was found that some items they were selling were actually cheap substitutes.