Police in Australia have raided the offices of the environmental activist group Greenpeace after three of its members destroyed an experimental crop of genetically modified wheat.

The activists wore mock hazard suits as they scaled a fence and cut down the crop last week at a farm in Canberra operated by the country's top scientific research agency. Greenpeace activists were quoted Thursday saying they are cooperating with the police investigation.

Scientists say the action has wiped out months of work to determine whether the modified grain could provide health benefits by improving blood glucose levels and lowering cholesterol. Officials insist the crop posed minimal risk to human safety.

However Greenpeace officials said they were acting to call attention to the “serious risks” posed by the research. They also cited concerns about government secrecy surrounding the project, which was soon to begin human trials.