Inland Revenue is cracking down on outstanding student loans - and has doubled its team working on overseas collections.
It's also putting more money into collecting debt in Australia and the UK.
The number of borrowers has risen by more than 5,000
The IRD's project lead Andrew Stott says about 150 people could face an arrest warrant.
"It's really about whether they're engaging with us or not. So if they're just ignoring all of our communications or they're leaving us no way to get in touch with them, then that's our last resort."
LISTEN ABOVE