Earlier this year Swiss biotech firm Syngenta warned it had accidentally sold the illegal Bt 10 in the US for four years, resulting in about 133 million kilograms of the corn making its way into food and feeds.
Reacting to the news, the European Commission quickly issued emergency measures whereby imports of corn gluten feed and brewers grain from the US can only be placed on the EU market if they are certified to be Bt 10 free.
Like Europe, Japan is now demanding the same.
Helping food and feed firms to overcome the hurdle of detection, Japan's Ministry of Agriculture, Forestry and Fisheries (MAFF) confirmed the use of Genetic ID's Bt10 testing for imports into Japan.
Genetic ID, a US firm, uses the Japanese government Bt10 detection protocol of MHLW and also the EU official protocol. These protocols are both third-party validated.
MAFF confirmed the test's acceptance under 17 SHOUAN 2395 which specifies that Bt10 testing at the export port must fulfill the following criteria: corn sample size must be more than 500g; the testing protocol must be third-party validated; the testing lab must be accredited by an independent third party under ISO17025 or an equivalent standard.
Between 2001 and 2004, Syngenta accidentally sold Bt 10 corn, mistaking it for the variety Bt 11, approved for food and feed use imports into the EU.
Both varieties produce a bacterial toxin that kills insects, using the same inserted gene and producing the same protein. The only difference is the location of the inserted gene, Syngenta claims.
Syngenta says it discovered the mistake for itself when it switched to a new quality control system that tests for DNA directly. Previously it had tested only for proteins, which meant the two varieties appeared identical.
In April the US department of agriculture fined Syngenta $375,000 for the slip up.
That previous testing methods failed to detect an illegal sweetcorn present in the food chain for the past four years will do little to reassure the already GM cynical consumer.
The European Commission, the executive arm of the European Union, has said it thought about 1,000 metric tons of the unauthorised strain of Bt10 corn, all grown in the US, had entered member states through animal feed, corn flour and corn oil.