As soon as you know you've lost your passport contact New Zealand Police and file a lost property report (within 24 hours if you will be claiming insurance).
Once you've filed your lost property report, take several copies of this report as you might need a copy for your embassy, visa transfer, and insurance.
You will then need to contact your nearest embassy, consulate, or high commission and ask for instructions on how you can obtain a new passport. You can find your nearest embassy, consulate, or high commission on the New Zealand Ministry of Foreign Affairs and Trade website:
Once you have your new passport please come into the International Office, in the north end of the Clocktower Building, and speak to the Student Visa Services team to see how you obtain a replacement student visa.
The costs involved in replacing your passport may be covered by your insurance policy. For help with your insurance claims, International Student Advisers are available from 11am until 2pm for walk-in appointments, or you can book an appointment between 2pm and 4pm or email firstname.lastname@example.org