One of the country's most senior prosecutors - part of an elite group of 16 Crown Solicitors - is under investigation after complaints about workplace conduct.
An investigation has been launched by the Solicitor General, New Zealand's top legal advisor, into the Hamilton Crown Solicitor's office after complaints from staff about the office work culture.
RNZ has learned that several staff have made complaints about the work environment at Hamilton Legal, where Jacinda Hamilton holds the Crown Warrant.
The complainants allege that a number of staff have left because of the nature of the work environment and there are concerns for the mental health of some staff still working there.
One source said about 10 staff had left the small team - there are only 11 prosecutors at Hamilton Legal - over the last two years.
RNZ has been told that some staff are also concerned about the way Crown prosecutions have been handled by the office and attitudes towards the defence and the judiciary.
Sources indicated that the Crown Solicitor Jacinda Hamilton was under scrutiny because she was the leader of the office and had a major role in setting workplace culture.
"Thanks for reaching out," Hamilton responded when asked about the investigation. "I'm sorry, I can't comment."
It's understood staff at Hamilton Legal approached Rachael Reed KC, via the National Friends Panel, a service offered by the Law Society. The panel is made up of lawyers who handle questions and concerns from their colleagues on a confidential basis.
Reed is named on the National Friends Panel list as one of the lawyers able to discuss "sensitive matters such as workplace harassment".
RNZ has learned, from government and legal sources, that Reed helped the complainants draft a letter to Crown Law, which escalated it to the Solicitor General. Reed declined to comment.
Sources told RNZ that the Solicitor General, the chief executive of the Crown Law Office and the government's chief legal adviser, has now launched an investigation, led by Maria Dew KC.
It's understood Dew's investigation will include interviews with senior members of the police, the defence bar and the judiciary.
Dew would not confirm or deny her involvement when contacted by RNZ, saying she could not discuss investigations she may, or may not, be involved with.
RNZ has been told Hamilton stepped back from staff management roles as the investigation began, although she is still prosecuting trials as Crown Solicitor.
Michael Heron KC, formerly a Solicitor General, has also been called in to act as a "sounding board" on the case, according to one senior legal source.
When approached about his role, Heron said all inquiries regarding the investigation needed to go through Crown Law.
Crown Solicitor's role
No Crown Solicitor has ever been removed from office in New Zealand.
There are 16 Crown Solicitors in New Zealand. All have a regional monopoly on prosecuting serious crime for the Crown.
Each Crown Warrant is issued by the Governor General.
Those appointed before 2013 have the warrant for life. Those appointed since have a 10-year term, but can apply to be reappointed after it expires.
In many centres, the Crown Warrant has been with the same firm for decades.
In Christchurch, Raymond Donnelly & Co has held the Crown Warrant since 1914. In Auckland, Meredith Connell has held the warrant since 1921 and in Wellington, Luke Cunningham Clere has held it since 1936.
The warrant is in the name of an individual - the Crown Solicitor - but the law firm assists them and the lawyers working under them are Crown prosecutors.
The Crown Solicitor holds a lot of power in the legal system in New Zealand, which is an international outlier in that all Crown Solicitors are lawyers in private law firms.
The most serious crimes - about 5 percent of all prosecutions - become Crown prosecutions and the Crown Solicitor has considerable sway over how they proceed.
While usually it is the police who lay charges, the Crown Solicitor can add to them, modify the charges or withdraw them.
About $41 million of taxpayers' money is spent each year on prosecutions conducted by the private sector lawyers who make up the Crown Solicitor network.
Crown Law's response
Solicitor-General Una Jagose KC confirmed to RNZ that she had commissioned Maria Dew KC to investigate allegations about the conduct of a Crown Solicitor.
"The allegations are best summarised as workplace conduct matters. They do not relate to the Crown Solicitor's performance as a senior prosecutor for the Crown," Jagose said.
Crown Law said the investigation was in response to an anonymous complaint which was not fully detailed.
"The Crown Solicitor in question is aware of the anonymous complaint and is cooperating in the investigation. The Crown Solicitor, however, has not yet been informed of the details of what is alleged or been interviewed by Ms Dew KC. Plainly no findings have been made yet."
Crown Law asked RNZ not to name the Crown Solicitor involved but RNZ considered it was in the public interest to do so.
"Confidentiality is essential to enable a fair hearing for both the complainants and the person complained about," Crown Law said in a statement.
"The Solicitor-General asks that media and the public respect the fair and impartial process that is underway and do not publish the name of the person complained about."
Crown Law said that the Crown Solicitor "continues in the role during the investigation," which is expected to be completed in the next few weeks.