A High Court decision to block applications to import and develop genetically engineered material has been hailed as a landmark by GE-Free New Zealand.

The High Court at Wellington ruled that the Environmental Risk Management Authority (Erma) should not have accepted applications for determination under the Hazardous Substances and New Organisms Act 1996.

It ruled that it should stop hearing and assessing any further applications.

"I think the error is such that Erma cannot continue to treat the applications as if they were valid," Justice Denis Clifford said.

GE-Free had taken both Erma and AgResearch to court in March.

Spokesman Jon Carapiet hailed the decision as one of the most significant decisions relating to GE in the last decade.

"This is the largest application that's ever happened in New Zealand - the wholesale genetic engineering of nine different species."

He said if the application had been approved, it would have been difficult for New Zealanders to know the risks or benefits of the trials, or whether the products "would end up in their backyard".

The public and farmers were against the "wholesale approach to genetic engineering of animals".

A Colmar Brunton poll at the time of the applications showed that 70 per cent of New Zealanders were against genetically engineered animals. Mr Carapiet said the Royal Commission into GE in 2001, and subsequent Governments, did not want an "anything, anywhere, anytime, go free and multiply" approach to GE research, but a case-by-case, careful assessment of the risks and opportunities.

AgResearch last year made four applications for the laboratory testing of human and monkey cell lines and smaller species of GE laboratory animals, and the development of GE cows, buffalo, sheep, pigs, goats, llamas, alpacas, deer and horses.

It wanted the livestock to produce antigens, biopharmaceuticals, enzymes, hormones and other products with possible health benefits and commercial applications. AgResearch said it was making a "suite" of applications to obtain all the possible approvals it might need for research and animal breeding to target production of high-value proteins in milk.

General manager science and technology Jimmy Suttie said the ruling prevented AgResearch from undertaking transgenic animal research effectively.

"We are challenged by this procedural issue as we will now lose valuable time in advancing our research and opportunities to capitalise on it."

However, he said AgResearch would revise its applications to Erma and submit alternatives. "We believe this is necessary to secure for New Zealand the opportunity to do this type of research and provide options for the pastoral industry."

Mr Carapiet said the court's decision would force the applicants and Erma to more fully analyse what they would do with an organism and how they would do it.

The Soil and Health Association said the decision was "a victory for New Zealanders" and showed Erma was failing Parliament's intentions.

"Every Erma-approved field trial, whether plant or animal, has fallen down on its conditions.

"For AgResearch to be loosely applying for a veritable zoo to play with was risky, unethical and went against New Zealand's point of difference in the world: clean green, 100 per cent pure and essentially GE Free," said spokesman Steffan Browning.

Erma general manager of new organisms Libby Harrison said the Government agency would not comment until it had had time to read and consider the High Court decision.

Meanwhile, all processing of AgResearch applications had stopped.