A man has been arrested for human trafficking and slavery after bringing Samoans to New Zealand to work illegally since the 1990s.

A 64-year-old Samoan national has been arrested and charged with human trafficking and slavery, following a lengthy investigation by Immigration NZ and NZ Police.

Allegations made by the victims include not being paid for work completed, having their passports taken, and being subjected to physical assaults and threats.

It is believed that his alleged offending has been ongoing since the 1990s, across the Hawke's Bay region.

The victims also allege that their movements were closely monitored and controlled by the man, and there were restrictions on both where they went and who they had contact with.

Immigration NZ assistant general manager Peter Devoy said the arrest was the result of around two years of detailed investigative work by INZ and NZ Police.

"We are absolutely committed to eliminating people trafficking in New Zealand," Devoy said.

"Today's arrest follows an extensive investigation by INZ and NZ Police, which has lasted more than two years."

"This reflects how seriously both of our agencies take these types of allegations, and our commitment to combatting Transnational Organised Crimes, including people trafficking."

Detective Inspector Mike Foster said the man charged had allegedly recruited people in Samoa, promising them "well-paid" jobs.

"Information collected during the joint investigation suggests that the man, who was seen as a respected member of his community in Samoa, targeted vulnerable people, who had limited education and literacy," Foster said.

"We have received valuable assistance from the Samoan authorities during our investigation, and I would like to extend our sincere thanks to them on behalf of both NZ Police and INZ."

* Anyone being forced to work here illegally for less than the minimum wage and/or excessive hours can contact INZ or the Labour Inspectorate, where their concerns will be handled in a safe environment.

People can also contact CrimeStoppers anonymously on 0800 555 111.