In response to the allegations, Immigration Minister Iain Lees-Galloway directed the Ministry of Business, Innovation and Employment (MBIE) to undertake "in-depth research on temporary migrant worker exploitation in New Zealand".
Samu was arrested following a lengthy investigation by Immigration NZ and 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 claimed the alleged offending had been ongoing since the 1990s, across Hawke's Bay.
The victims also claim that their movements were closely monitored and controlled by Samu, 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."
Lees-Galloway said this action demonstrates why this Government has made cracking down on migrant exploitation one of our top priorities in Immigration.
"This reflects how seriously both of our agencies take these types of allegations, and our commitment to combating Transnational Organised Crimes, including people trafficking.
"There is no place for exploitative practices in New Zealand. Migrant workers have the same employment rights as all other workers."
Devoy said the situation was "significant" but because the matter was before the court, he could not go into any detail of the case, including any instances of threats.
Devoy said some victims have been "under his control" for some years.
He said INZ became aware of this through talking to one of the victims about two years ago.
"This is a new low for New Zealand," Devoy said. "This is about a labour contractor."
He added that the people running the orchards probably didn't know about the alleged offending.
He said this was the fourth time INZ had charged someone with people trafficking, but it is the first time the police became involved.
Devoy said he believes "the combination of slavery and the treatment of these people sets [this case] apart."
INZ has been working with the Samoan police and there would be more working between the two.
"It will be incumbent on us as New Zealand, for us to be more aware what's going on in the labour force," Devoy said.
INZ is working to limit this happening again, he said.
Lees-Galloway was briefed on the case before INZ made it public today.
Detective Inspector Mike Foster, Eastern District Police said there were 10 alleged victims, who are spread across New Zealand and Samoa.
Foster said between 15 and 20 people have been working on this case in the past two years.
Samu will be the only one to face charges, he said.
Foster said it was an "easy choice" for the police to get involved in the case after INZ talked to the first victim.
He said Samu had allegedly recruited people in Samoa, promising them "well-paid" jobs.
"Information collected during the joint investigation suggests that the accused, who was seen as a respected member of his community in Samoa, targeted vulnerable people, who had limited education and literacy.
"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.
