Police certificates must be provided from your country (or countries) of citizenship, as well as any country you have lived in for 12 months or more in the last 10 years.
https://www.immigration.govt.nz/new-...ficates/slider
You were there studying for your BSc. It is going to be obvious to anyone seeing your whole academic record that you MUST have been in the country for more than one year in total.
When you put in an application to INZ, it is a legal document, and by submitting it, you are declaring that everything on it is the truth. If it is later discovered that something is not true, INZ can interpret this as fraud, which would get that application refused, and cause difficulties for other visa applications in the future.