The operators of the country's oldest organics unit fear it could risk losing its certification after a genetically modified field trial in Canterbury breached its operating conditions by allowing a brassica plant to flower.
The discovery was made at a site in Lincoln used by Crop and Food Research Institute, now part of Plant and Food Research.
The breach occurred one year into a 10-year trial of cabbages, broccoli and other brassicas that had been genetically modified to resist caterpillar pests.
Some environmental groups are worried that pollen from the flowering plant could have been spread to two certified organic properties which are within bee-flying range of the site.
One of the properties, Lincoln University's Biological Husbandry unit, was growing brassicas, but it is not known whether the other, Heinz-Watties' Kowhai farm, had brassica crops at the time.
The chair of the trust that leases the biological husbandry unit, Jon Manhire, says there is a risk the site could lose the organic status it has had since the 1970s.
Mr Manhire said if organic certifiers are concerned they may require tests to be carried out to determine whether the crops have been contaminated, which would be expensive and disruptive.
The Plant and Food Institute has said that the breach is unlikely to lead to cross pollination with other crops.
However, it has put the GM brassica trial on hold, along with another GM onion field trial which had been due to start soon, until Biosecurity New Zealand completes an investigation.
Organics Aotearoa New Zealand chief executive Jon Tanner would like to see testing done to ensure there has been no contamination from the site to neighbouring properties.
Mr Tanner has urged that stronger procedures to contain such trials.
