Hundreds of Japanese have been taken ill after eating frozen food contaminated with pesticide.

Food maker Maruha Nichiro began recalling 6.4 million packs of frozen food on December 29, saying it found some contained high levels of pesticides. The company has received hundreds of thousands of calls about the problem.

Public broadcaster NHK said information from local governments showed 356 people had suffered vomiting, diarrhoea and other problems after eating the food.

Maruha Nichiro says it has retrieved about 1.1 million packs so far. Police are investigating how the products were contaminated with the pesticide malathion, reportedly by up to 2.6 million times the allowable limit.

Malathion is used in farming and gardening and also to kill fleas on animals and people. At high enough concentrations, it can cause death.

There have been no reports of life-threatening illnesses from Maruha's products, but the contamination has further shaken public confidence undermined by various food quality scandals.

Late last year top-notch hotels and department stores apologised after it emerged some of the items they were selling were actually cheaper substitutes. Local magazines are also warning that trade agreements with other countries like China might lead to imports of contaminated or otherwise unsafe products.