Police say it is possible they have uncovered a human trafficking and migrant exploitation ring in Hawke's Bay, sparked by a "distraught" victim raising the alarm.
A 44-year-old man facing three charges of rape, and one of unlawful sexual connection, was remanded in custody and granted interim name suppression at Hastings District Court on Thursday.
He was arrested following a joint operation between Hawke's Bay police and Immigration New Zealand, called Operation Wentworth.
The operation began when a victim contacted police "after fleeing and asking for help", Detective Senior Sergeant Sally Patrick told RNZ.
"She was distraught," Patrick said.
"She went to a person that she trusted, and then they phoned police and we attended straight away."
The woman accused the man of rape, and Patrick said the other information she gave led police to believe migrant exploitation and human trafficking were also at play.
Human trafficking charges would likely be laid in the new year - but police first had to follow due process and seek the solicitor-general's consent to lay those charges, which took some time, Patrick said.
Police "highly suspect" there were other victims - and other potential perpetrators, too, she said.
They had so far carried out three search warrants in Hawke's Bay, and two migrants were served Deportation Liability Notices as a result.
The investigation might go outside the region, and police were "potentially" looking at a human trafficking and migrant exploitation ring, Patrick said.
"That's why we are reaching out to any victims to get in contact, and that's not always easy," she said.
"The type of exploitation that they're subjected to makes them also scared to come forward."
That could be for a number of reasons, she said - including fears they might be deported, not having financial support, and if English was not their first language.
"We want people to know that they can come forward and police will absolutely speak to them and try and support them where we can."
The man is due to appear in Hastings District Court again next week.
Anyone with information can contact police on 111 and quote file number 231129/1010 or call Crimestoppers on 0800 555 111, police said.
Immigration New Zealand declined to comment further, as the investigation is ongoing.