Police and other government departments are reluctant to hand over public information because of potential embarrassment to politicians, says Police Association president Greg O'Connor.
"Anyone who is dealing with the public sector at the moment - there tends to be an attitude of making people work very hard for their Official Information Act information," he said.
Mr O'Connor spoke out after a police research contract was made public showing academics were being forced to accept strict conditions before getting information for research. The contract told researchers they would go on a "blacklist" if they failed to show a draft, work on "negative results" with police and work with police to "improve" the research "outcomes".
The issue was made public by University of Canterbury criminologist and lecturer Dr Jarrod Gilbert, who sought crime data to study links between law-breaking and licensed liquor outlets.
Mr O'Connor said the public service - including police - had adopted a defensive posture when it came to releasing information.