Illegal migrants sometimes put themselves into situations where they can claim to be victims of human trafficking as a way to get into another country, an Auckland academic says.
In New Zealand, 36 people have been officially identified to be victims of human trafficking.
According to Immigration New Zealand (INZ), the trafficking cases detected to date involved migrants from the Asia-Pacific region travelling to New Zealand willingly in order to work and have a better life.
Australian Home Affairs Minister Peter Dutton warned this week that New Zealand was being marketed as a destination for illegal immigrants.
This followed an interception by Malaysian police of a modified tanker off the Malaysian coast that was carrying 127 Sri Lankans, believed to be illegal immigrants heading for Australia and New Zealand.
Despite global estimates that there are about 40 million human trafficking victims, AUT University Professor of Diversity Edwina Pio believes the number of true victims was much smaller.
Pio warned against a "one-dimensional concept" of human trafficking which focused on a "stereotypical version and master narrative of the deceived, battered victim under continuous surveillance, needing to be rescued by the police".
She said some "victims" would have chosen this pathway as a route to a better lifestyle, with dreams of a better future as compared to their home countries.
"Access to a world through selling sex or selling one's manual labour as irregular workers is the pathway to realise the kind of person they want to be, which is a far cry from the powerless victim portrayed rather than the agency of individuals as part of a migration project," Pio said.
"It is highly likely that only a minority of 'victims' are forced."
Pio said "co-offending" or "co-migration" were key conduits of modern mobilities and people distribution as they built on kinship and ethnic ties.
"The violation of human rights must be viewed within the context of societies within which they operate and are embedded," she said.
"Also with the knowledge that this is a global phenomenon with transnational trafficking networks and a fruitful terrain for profit."
INZ's trafficking in persons programme manager Rebecca Miller said there were "many myths, misconceptions and stereotypes" associated with human trafficking, including in relation to victims.
"It is not until people arrive in New Zealand that it becomes clear they were deceived or being exploited," Miller said.
"Victims often have certain degrees of freedom. Coercion or control is achieved through debt bondage, isolation, fear, threats, withholding of passports, intimidation or manipulation of immigration status."
Miller said human trafficking involved manipulation of victims that resulted in serious undermining of a person's personal freedom and ability to make choices for themselves.
"Human trafficking is a serious crime and amongst the most serious human rights violations," she added.
"It is a serious offence that the Government takes seriously."
To protect the privacy of victims, Miller said the agency would not be releasing any information on the immigration status or whereabouts of those who have been identified as human trafficking victims.
The first people trafficking charges in NZ were brought by INZ in August 2015, and Faroz Ali became the first in New Zealand's history fo tbe convicted for the crime.
Barrister Mohammed Idris Hanif, who provided legal advice to Ali, was himself convicted earlier this month for offences relating to knowingly providing false and misleading information to INZ.
INZ's assistant general manager Peter Devoy said: "Due to the need to protect any ongoing INZ operations in his space, we are unable to reveal any further cases that may be underway."