In order to be a private investigator in New Zealand you must first apply for a license. If you have any prior issues with the law it is not going to work in your favor because any member of the parliament or the police academy, can object to your application within one month of you applying. This eliminates a lot of fraudulent claims of being a private eye as well as removing any shady characters.
There is a suitability process that a potential private investigator in New Zealand is subject to and this is based on a number of qualifications. One of the top qualifications is that based on your personal character, fitness as well as financial position. This is generally seen as a public interest at this stage due to the very nature of the job. If the applicant has had a previously held license and had it revoked for any reason, the application will be thrown out.
That goes without saying that if you have any convictions within the past five years of applying for a license, you will not be granted. Any person applying to be a private investigator in New Zealand that has displayed dishonesty in those past five years, imprisonment or a questionable background...