A major report on the threat of agricultural bioterrorism is being delayed as US government officials wrestle with the National Academy of Sciences over whether its release would provide information that could be useful to terrorists.

The academy's report, Countering Agricultural Bioterrorism, was commissioned in autumn 2000 and was due to be released in June. But its publication has been bogged down in wrangling between the academy, the US Department of Agriculture and the Office of Homeland Security.

The academy is keen to release the report — which was agreed by a committee chaired by Harley Moon, an animal-disease specialist at Iowa State University at Ames — in full. But government officials want to cut parts of it.

Members of the committee who had security clearance were provided with at least one piece of classified information during their study, so the study had to undergo a declassification review before it could be released.

Jim Cook, a plant pathologist at Washington State University at Pullman and a member of the committee, who also sits on the academy's governing council, says that the stand-off is unprecedented. “We've never had this kind of difference in perspective — almost a squaring off — between a government agency and the academy before,” he says.

He adds that it reflects a difference in outlook between plant scientists and government officials on countering agricultural bioterrorism. The American Phytopathological Society, for example, has argued that trying to constrain information about plant biology is futile, and that the government should prepare to counter possible attacks. But some government officials favour constraints on information.

As far as the disputed report goes, “the final decision will be the academy's”, says Bill Colglazier, its executive officer. He hopes that it will be published later this month.