GE Free New Zealand says it is very worried about what will happen to animals used in experiments at AgResearch's Ruakura campus, in Hamilton, now it is to be scaled back.
Scientists at the country's largest Crown Research Institute have been working mainly with genetically modified cattle to produce therapeutic proteins in milk.
AgResearch is to expand its operations at Palmerston North and Lincoln, and reduce its Dunedin and Hamilton campuses.
GE-Free president Claire Bleakley said there is no information on the future of the animals at Ruakura.
But Agresearch chief executive Tom Richardson said the animals are not going anywhere under the current proposal and the research will continue.
Dr Richardson had no response to comments by GE Free New Zealand about high rates of abortion, deformities and sterility among the transgenic animals, saying those claims were well canvassed last year.