Scientists have condemned Greenpeace for destroying a trial crop of genetically modified (GM) wheat in Canberra.

Scientists say the destruction of the trial crop in Canberra's north yesterday is not only reprehensible, but also hypocritical.

CSIRO genetically modified the wheat to enhance its nutritional value, and it was to be used in the first human trials in Australia.

It was also Australia's first outdoor crop trial of the enhanced wheat.

But Greenpeace says it took the dramatic action to destroy the crop using whipper-snippers because of health concerns, the risk of cross-contamination and the secrecy surrounding the trial.

Professor of Plant Science at the University of Adelaide Mark Tester says the technology is poorly understood and Greenpeace's attack was irresponsible.

Professor Tester says the activists' reasoning does not stack up.

"With one hand they're demanding we do field trials and test the efficacy and safety of these crops, and when we go off to try to do that, they destroy them," he said.

"These CSIRO field trials that have just been destroyed, they were altering plant genes in plants, they were trying to improve the health properties of wheat."

Professor Tester says the crop was not an appropriate target for Greenpeace's "anger".

"Because it's new people have concerns about that, that's absolutely fair enough to ask questions and to ask hard questions about GM," he said.

"But those questions should be intelligent and they shouldn't be couched in terms of all GM in some sort of neo-religious belief way... they should not be just all GM is bad - that's just a crazy statement."

Associate Professor in Politics at the University of New South Wales Sarah Maddison says the vandalism is likely to be just the beginning of Greenpeace's campaign against GM crops.

"This incident alone will not be effective," she said.

"I think... this may well result in litigation against Greenpeace. A court case will certainly allow the activists to air their concerns more fully [and] will give the media the opportunity to report more accurately on concerns."