A review into the police vetting system has revealed the extent to which people's sensitive private information can be passed on to a third party.
The scope is so wide it can go beyond a person's criminal record, and include details about their mental health and even information that has been subject to suppression orders.
This means police are vulnerable to major legal risks, and a review into the system has suggested the creation of a legal framework to act as a guideline in decision making.
Both the Independent Police Conduct Authority (IPCA) and the Office of the Privacy Commissioner (OPC) were requested by police to review the vetting system, which deals with around half a million requests each year.
According to the police website, vetting provides "criminal history checks and other relevant information on potential and current employees or volunteers to approved agencies that provide care to children, older people and vulnerable members of society in New Zealand". It also provides criminal history checks for visas and work permits.
Privacy Commissioner John Edwards says where police are faced with difficult decisions there is not a sufficient legal framework to provide clear guidance.
"Many people who consent to be vetted don't realise what it involves. They may think for example that it's just a check on relevant criminal convictions, but actually the police will look deep into their files and any contact that you've had with police might be taken into account."
The review found such information could include details which police received in confidence that a person may not in fact be aware of, and which haven't been tested before a court, and could be highly prejudicial.
Mr Edwards says in some cases police are able to release information subject to suppression orders to employers.
"We are a bit concerned about the legal basis, particularly for example where a suppression order is granted for the benefit of the accused, so to excuse them from any prejudicial effect, because if that information is then taken into account for a vet you've in effect got police overriding the express decision of a court."
There are also concerns around releasing mental health information.
"I'm concerned that police may be in effect making clinical judgments that they may not be in fact qualified to make."
The Privacy Commissioner stressed that while these types of cases are small in number, they are significant enough that a stronger framework must be a priority.
"I have some sympathy for police because they could get it either way. They either sit on information and say well we're not going to release that and find that the person goes on to present a risk, or they release information that they haven't verified that they perhaps should have made further inquiries about and somebody has an adverse result as a consequence."
Superintendent Steve Kehoe said police welcomed the report's findings.
"Police vets over 500,000 New Zealanders every year and has an obligation to achieve a balance between protecting the most vulnerable in our communities, and protecting the privacy of individuals who are the subject of vetting applications," he said in a statement.
"Police has already implemented changes and begun taking steps to address a number of issues identified during the review and the recommendations made in the report."
Steps include ensuring the current approved agencies meet the criteria, appointing a dedicated panel member "to provide continuity to the review of vetting applications" and speeding up vetting by increasing staff numbers.
Police will analyse the findings of the review and make recommendations to the Police Minister.