The Department of Internal Affairs is investigating dozens of alleged poker machine rorts involving millions of dollars of charitable funds.
A request under the Official Information Act for details of those investigations has been declined by the department, on the grounds any release could prejudice each case.
However a spokesman confirmed the department was investigating 50 alleged breaches of the Gambling Act, many involving conflicts of interest over grant money.
Problem Gambling Foundation chief executive Graeme Ramsey said he was not surprised the department was investigating so many rorts, reinforcing views "on just how broken this system is".
Given the number of investigations, "millions of dollars" were likely to be at stake, and any trustee found guilty of such rorts should be prosecuted.
"It is about holding people accountable," he said.
The Foundation supported the Gambling Harm Reduction Bill, submitted to the Parliamentary ballot by the Maori Party, which includes the phasing out of pokie trusts, with grants to be distributed by local authorities.
Labour Party internal affairs spokesman Chris Hipkins said the system which distributed pokie machine profits was fundamentally flawed.
"We need to take some bold steps and change the way the system operates ... it is open to rorting."
Mr Hipkins said dodgy trusts involved in rorts were able to change their financial arrangements at such speed they were always one step ahead of a "slow-moving" department.
Asked what changes he would like to see, Mr Hipkins said he wanted a more transparent system, with grants distributed by local authorities.
Internal Affairs Minister Nathan Guy said he was concerned "that this number of investigations is necessary and I'm disappointed in the behaviour of some gaming groups".
"I've reminded gaming machine operators that they exist for the sole purpose of raising money for the community. The money they raise is not theirs, it is money they hold in trust for the community."
