Officers in an elite unit set up to target the biggest criminal threats to New Zealand fear internal reprisals if they tell police bosses of "inappropriate conduct" on the force.
The detail has emerged in a police employment survey which revealed staff concerns about "respect and integrity" at the Organised and Financial Crime Agency of New Zealand.
Police Minister Anne Tolley last night stood by the unit, which was embarrassed in two high-profile operations last year that involved accusations of unlawful police practice.
"I believe Ofcanz does its very best in every investigation it works on. It is often involved in difficult and complex operations - and learns lessons from every case."
The High Court last year found Ofcanz had carried out an unlawful search of Kim Dotcom's mansion after organising a dramatic airborne assault. Then in another High Court case 21 people were freed after an investigation into the Red Devils featured questionable tactics, including the manufacture of a fake search warrant.
Ofcanz has also had to deal with an internal merger which led to friction after an Auckland specialist department targeting organised crime, which had been highly successful against the drug trade, was folded into the new group.
Ofcanz deputy director Detective Superintendent Ray van Beynen dismissed links to the Dotcom and Red Devils cases. He said police were taking no disciplinary or employment action in connection with either case.
He said concerns about staff raising matters of inappropriate conduct "related to an internal staff management issue concerning one individual employee". It had since been dealt with.
Police Association president Greg O'Connor said the merger led to pressures emerging through "different philosophies and ways of doing business".
He said the Dotcom and Red Devils cases were also a factor.
"Nobody likes being seen to be part of something that is under heavy criticism - and they were."
A defence lawyer familiar with Ofcanz, speaking on condition of anonymity, said there were concerns around integrity, particularly because of the secretive way the agency operated.
Recent cases including the high-profile bungles showed "all the ingredients ... for this outfit to go totally rogue if something's not done to keep it in check".
Clarion HR chief executive Clare Parkes, an expert in employment surveys, said the sharp difference in survey results in just a year "should be a concern to any organisation".
"This shows an increased lack of confidence in the environment relating to trust and transparency."
Just 58.2 per cent of staff were confident in raising concerns about any actions or behaviour that made them uncomfortable at work, down 14.2 points from the previous year. The figure was well below the improving average of 68.4 per cent across all police.
"Respect and integrity" were "top of mind" issues for Ofcanz, wrote analysts for Kenexa, who published the independent New Zealand Police workplace survey for 2013.
The survey also highlighted a large discrepancy between perceptions of accountability and poor performance.
While 70 per cent of Ofcanz staff agreed colleagues were held accountable for poor performance - an increase of 14.8 per cent on last year - just 38.8 per cent said poor performance was "dealt with effectively".
The report also raised concerns about the handling of bullying and sexual harassment with male staff saying they did not see any incidents they believed "had been addressed effectively". Of female staff, just a quarter had similar concerns.
Green Party police spokesman Dave Clendon said the police had "got it horribly wrong" in the Red Devils case. The survey result "makes you wonder at the culture of the place".
The Megaupload founder was arrested after an airborne assault on his mansion by machinegun-toting anti-terror police. The warrant used to storm and search the house was declared unlawful - a bungle which led to the Ofcanz admission they had brought the GCSB in to illegally spy on Mr Dotcom. The disastrous operation was carried out at the request of the FBI, which wanted to extradite Dotcom to the US on copyright charges.
Red Devils case
In Operation Explorer, an undercover agent worked his way into the Red Devils motorcycle gang in an 18-month investigation. But the case was thrown out by a High Court judge when it was discovered Ofcanz had faked a prosecution against the officer when they feared his cover would be blown. Police bosses said they believed they were acting with the permission of the then chief District Court judge. However, Justice Simon France ordered a stay of proceedings against the Red Devils group as he believed "a fraud is being committed on the courts".