Five migrants have been sent home since September for unlawfully working in the sex industry in Nelson and Marlborough.
During an investigation last year, INZ visited 57 small owner-operated brothels across the country. No brothels were visited in the top of the south.
As part of that investigation, 66 migrant sex workers were identified. Of those, 36 were on visitor visas, two on student visas and the remainder on resident visas.
All sex workers but one were Chinese nationals.