Kiwis are wrong to think human trafficking isn't happening in New Zealand, says a former US Department of Justice prosecutor.
Jim Lord spent 20 years bringing traffickers in the US to justice, and he told The AM Show on Friday there's a "sense of complacency" that it's not a problem here.
"I think it's a combination of the fact you're ranked in tier one on the US State Department list of countries that have a problem with human trafficking - which means you're not suspected of having a problem. But at the same time you don't have the laws and regulations in place to deal with it."
There have been a number of high-profile cases in the news recently, and Immigration Minister Iain Lees-Galloway in April said "modern slavery is hidden in plain sight".
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"Although it is very difficult to detect these crimes, we know it is happening," he told NZME.
"Human trafficking generally involves a promise to lure immigrants into a more developed country with a promise of work and good wages," said Mr Lord, consultant for Dow Jones.
"They have to pay a lot of money for the transport to get here, then when they get here they're employed at substandard wages to the extent they're never able to pay off the trafficking debt."
New Zealand's first-ever human trafficking conviction didn't come until 2016.
Over the past two decades New Zealand has had a large influx of migrants from Asia. Mr Lord's specialty was prosecuting traffickers from China, which he says are run by organised crime syndicates - think the Triads and the Tongs - and are "the most heinous" in the world.
"There was a huge problem in the US with Chinese immigrants paying huge sums of money with a promise of a better life in the US, then they were trafficked oftentimes in container ships. I handled one case where four of the immigrants arrived dead because of the conditions in the container that they were transported in."
Many end up working in prostitution.
"Women were being brought into the US with a promise they'll be working in garment factories at standard wages, and then they were enslaved into prostitution."
He's not sure if the problem exists to the same extent in New Zealand, but believes it's likely "given you have a large immigrant population here now from China".
Mr Lord says New Zealand should take a close look at the UK's Modern Slavery Act, and also consider stricter vetting of Kiwi companies' supply chains, to ensure there is no human trafficking or slavery involved - particularly in Asia, a growing market for New Zealand goods.
Immigration NZ is currently investigating the extent of trafficking and slavery in New Zealand.