Anyone from AUS & familiar with rules of flying international??

So we're planning to travel to New Zealand but my brother has some unpaid fines from being a public nuisance (whilst intoxicated) just wanting to know can we still travel to New Zealand for 2 weeks or will the fines need to paid beforehand? We're leaving next month and his unable to pay for them that soon,  Not to mention his officially from New Zealand, not Aus, we're going back home for a visit .. Tried google yet can't Find the answer I'm looking for, anyone else experienced this or know how it works?