The Health and Welfare Ministry on Wednesday said tests have confirmed the presence of banned StarLink corn in food products sold at retailers in Japan.
The products containing the genetically modified corn are no longer on sale, the ministry said.
The tests were conducted after a domestic consumer group reported finding food containing StarLink on supermarket shelves last month.
The food products in question were made from corn products processed from some 5,500 tons of corn imported from the United States in January.
A total of 199.5 tons of the corn-based products were produced in Japan and 11 Japanese companies used them for production of foodstuffs including beer, sweets and bread.
StarLink corn contains a gene that creates a germ-killing substance that is believed to cause allergic reactions in some humans. It is approved for use only as animal feed in the U.S., the sole country to produce it.
In Japan, StarLink is banned while the ministry tests its safety for application to food products.
As 38,000 more tons of corn imported from the U.S. in February and March have been confirmed to contain StarLink, the ministry is trying to determine if other contaminated products are also on sale.