Suspected GM Sweet Corn - Questions and Answers
Suspected GM Sweet Corn
Media Questions and Answers
When did MAF first become aware of this issue?
On Thursday 26 June 2003 the Food Safety Assurance Manager of a company in the Gisborne region contacted MAF Biosecurity Authority. The company had received notification from its Japanese importers its their processed packaged corn kernels had tested positive for the presence of Genetic Modification (GM) by a Japanese laboratory.
The next day, Friday 27 June, MAF received the test results which were in Japanese. The tests had also been conducted on a pizza topping mix containing a number of other ingredients. Immediately arrangements were made to re-test the topping mix in an independent Japanese laboratory and to get a translation of the initial test results. The re-test results and the translation were received on Tuesday 1 July. MAF then moved to secure samples of the original seed lines together with samples of the product exported to Japan. These were sent to AqriQuality in Melbourne.
MAF received these results on Friday 4 July and then proceeded to brief Ministers, officials and the New Zealand public.
What has been done to verify the results?
So far MAF has secured seed and product samples from the New Zealand company and arranged independent testing through AgriQuality’s GM testing facility in Melbourne. This is a highly sophisticated testing laboratory. The original samples tested are being re-tested to confirm the initial results. When we have further results on the nature of the samples we will then have a better basis for decision making.
How do we test imports of seed?
The New Zealand testing regime is one of
the strictest in the world.
MAF tests imported seed for growing in the environment at the border and if there is any indication of unauthorised GM content it is not allowed in. MAF tests every batch of corn (as well as maize seed) from all countries that grow GM crops as it comes into the country and requires phytosanitary certificates from all other countries stating that the seeds are GM free. A consignment that has been tested offshore in a MAF-accredited laboratory, according to the method in our import protocol, will not be tested again unless there are genuine grounds that GM seeds are present. This means that seed from non-GM as well as GM producing countries is certified GM free before it is allowed into the country.
Last year the sample sizes for testing for inadvertent GM content were increased from 1400 to 3200 seeds. This means that the current testing process will detect the presence of GM so that MAF will be 95 per cent confident that any consignment with a level of GM contamination of 0.1 percent (one seed in a thousand) will be detected.
So why wasn’t it picked up in the import testing process?
Unless every single seed is tested (thereby destroying it), we cannot guarantee 100 percent GM-free seed.
This suggests that the laws can’t prevent GM coming into the country inadvertently.
Testing at the border is rigorous and when inadvertent GM content is found, we act immediately to control the situation.
How come the tests results vary in terms of positive and negative?
The tests used to check for the presence of GMOs are highly sensitive and capable of detecting contamination from a number of different sources.
How else could these seeds have been contaminated?
There are several possibilities, such as contamination in harvesting and processing equipment; contamination in the laboratory and cross-pollination from neighbouring crops.
How could cross-pollination have occurred?
Wind-borne pollen from adjoining Zea mays crops may have contained GMOs. MAF investigation are underway to determine the scale, location and proximity of these plantings to other Zea mays crops.
Is there any connection to the earlier GM maize issue at Pacific Seeds in Gisborne?
MAF Biosecurity is obtaining information on the location, quantity and types of field plantings associated with this investigation.
When will an audit of the company start?
A quality assurance audit of the company will be carried out over the weekend, and the company is very happy to host the audit team. The NZFSA and a member of Plants Biosecurity will conduct the audit and preparation of a question checklist has started. In the initial stages of an investigation such as this, priority is given to securing the product and testing it to see whether or not it is contaminated.
The audit needs to be undertaken carefully so that all the required information is collected, recorded and fully documented.
Will MAF trace the corn seed from the original consignment?
Yes. MAF's investigations will include the seed company responsible for the original importation. All sites where this corn has been grown will be investigated.
How many other countries are affected by the exports of this sweetcorn?
MAF investigators are conducting a full audit of the company involved, If shipments have been made to other countries, these Governments will be advised by MFAT.
MFAT is in liaison with its Japanese counterparts.
For further information about The New Zealand Food Safety Authority visit
For further information about MAF protocols visit