District health boards are consistently failing to respond to Official Information Act requests within the legal timeframe, the State Services Commission says.
New figures released by the commission show New Zealanders filed more than 40,000 Official Information Act requests in the year ending June 2016.
Organisations subject to the Act have 20 working days to respond to a request but routinely extend that deadline for consultation.
The State Services Commission said 91 percent of requests were dealt with on time.
But the Taranaki DHB responded on time to only 69 percent of requests, Canterbury to 60 percent, and Hawke's Bay to just 38 percent.
The commission said DHBs were consistently failing to respond within the legal timeframe and needed to do better.
Labour Party health spokesperson Annette King argued ministerial meddling was slowing down DHBs' responses.
"Any OIAs that go out - the minister must know about them, so they acutally go through a process where the minister is having some control over what is released, when it's released, how it's released.
"So I believe, there is a fair level of political inteference in terms of the release of DHB information."
Health Minister Jonathan Coleman said those comments were "just political nonsense".
Glenn Barclay, national secretary of public service workers' union the PSA, said the 91 percent on-time response rate showed public servants on the whole were doing their bit for open and transparent government.
Mr Barclay said eight or nine years of a freeze on hiring administrative and clerical staff in DHBs "will not have helped the situation".
"Obviously they can do more to lift their game, but obviously there's a resourcing issue there as well."
OIA complaints
Statistics released by the Ombudsman showed police and Corrections had the most complaints against them over handling of OIA requests in the second half of 2016.
Of the 538 complaints to the Ombudsman, 75 were about police and 49 related to Corrections.
Chief Ombudsman Peter Boshier said it was crucial the volume of requests the two agencies deal with was taken into account.
"Police and Corrections are an example of agencies who receive and process thousands of requests each year.
"So I just want to be careful and balanced in saying that what we see is a small portion of the actual requests that they have to deal with."
State Service Commission figures show Te Puni Kōkiri, the Māori development agency, was the worst performer out of government ministries - responding to only two-thirds of OIA requests on time.