GE Free New Zealand is alarmed at the implications of a court case in Western Australia, which it said highlights the lack of protection against contamination from genetically modified crops.
A West Australian organic farmer who sued his neighbour for allegedly contaminating his farm with genetically modified canola, lost his case.
The judge ruled that the neighbour could not be held held responsible for the farmer losing his organic certification.
There are no commercial GM crops grown in New Zealand.
But GE Free New Zealand president Claire Bleakley said the decision has caused shock waves.
"Farmers livelihoods and the choice to farm in the way they want will be destroyed if legislation gives free license to GE contamination. And this finding highlights the inability of non-GE and GE crops to co-exist.
"There is a lack of redress and a severe loss of livelihood if GE crops cause pollution or are introduced into New Zealand."
Ms Bleakley said it reinforces the need for New Zealand to stay GE free.