The Ombudsman's Office has warned of "highly dangerous" moves by the Government to keep information secret by drafting laws to avoid the Official Information Act.
Chief Ombudsman Dame Beverley Wakem says she is concerned at the increasing number of officials in government agencies who fail to understand the constitutional importance of the legislation.
She pointed to several "reprehensible" attempts in the past year by officials to disallow Official Information Act requests for drafts of legislation, in particular on partial state asset sales, charter schools and changes to mining permits.
"I think it's the beginning of something that's highly dangerous," she told the Herald.
"If this goes on, we will be appearing much more regularly at select committees when these things appear in the form of a bill, and making our views heard loud and clear."
The Ombudsman's Office argued this year that state assets associated with the Mixed Ownership Model Act would still be 51 per cent owned by the public and should remain subject to the Official Information Act (OIA).
The Government opposed this on the grounds of commercial sensitivity, and said stock exchange watchdogs would keep the energy companies honest.
Dame Beverley said these watchdogs were concerned only with companies' balance sheets and did not monitor corruption or other unethical behaviour by businesses.
The Ombudsman's Office was not consulted on the proposal to introduce charter schools in New Zealand, and Crown Mineral Act reform was initially not subject to the act.
"There's a real creep-in here of a philosophy that these things have got to operate in a fully commercial environment and be competitive," Dame Beverley said.
"Well I ran a [state-owned enterprise] - Radio NZ - and was subject to the act and never found it a difficulty vis-a-vis my competitors in the marketplace to comply with the law."
A Law Commission review of the OIA said the refusal of information on the grounds of commercial sensitivity needed to be tightened.
Justice Minister Judith Collins said she was considering the commission's report and would respond this year.
The Ombudsman's Office received 1236 OIA complaints in the past year - a 25 per cent increase on 2011-12 and the most in 11 years.
Dame Beverley said her office was struggling to keep up with requests, and had a third of the budget it needed.
The most common OIA complaint was a delay by agencies and departments in releasing information.
Members of the public, the media and MPs laid the most OIA complaints about the police, Earthquake Commission, Accident Compensation Corporation and Department of Corrections.
* 22 per cent increase in complaints to the Ombudsman's Office in 2011-12.
* 1236 OIA complaints in 2011-12, the most in 11 years.
Where Official Information Act complaints arose:
* School boards of trustees: 239 complaints (199 from one person)
* The police: 130
* Earthquake Commission: 54
* Accident Compensation: 53
* Corrections Department: 48.