The Immigration Service says people from Samoa and Tonga make up the biggest group among overstayers in New Zealand. The official total is more than 16,000.
New figures show that about 4000 Samoans and nearly 2500 Tongans are overstayers, along with almost 200 Chinese and 700 people from Fiji.
The figures were issued prior to a meeting between Immigration officials and Pacific Island leaders in Manukau City on Wednesday.
Radio New Zealand's Pacific issues correspondent says the figures contradict a popular view that Europeans comprise the bulk of overstayers.
Massey University immigration specialist Professor Paul Spoonley says the overstayer problem moves to the fore in an economic downturn when jobs are being lost.
Professor Spoonley says addressing the issue will be difficult because not everyone will meet the criteria to stay.
In a statement, the immigration service says the meeting is a way to move the issue forward and there are no plans to round up overstayers and deport them.