Japan will allow food products to contain genetically modified corn in levels up to 5%, the nationwide Mainichi Shimbun newspaper reported today.

The newspaper reports that the rule will form part of new safety guidelines to take effect April 1. The government decided to set a threshold for high-tech corn after new technology made it possible to detect it in processed foods.

The decision to allow the GM ingredient limit in processed foods comes as a surprise. The Japanese have been strong opponents to the presence of any genetically modified organisms in food. Japan has closely regulated the biotech food sector citing concern over possible health risks from eating products made from it, but commercial concerns look to be behind the government's thinking.

The discovery of genetically modified StarLink corn in snack products caused a national storm last year.