Using NZ residents and citizens to front for advertisements, and moving out of brothels and operating in private residences - these are some of the moves illegal sex workers are using to evade Immigration NZ's visa crackdown.
The crackdown has seen a further 11 people nabbed for providing commercial sexual services and facing deportation.
This is on top of 27 Asian sex workers who have already been deported or voluntarily removed.
A Korean sex worker, who is here on a visitor visa, told the Herald that some migrant sex workers were taking steps to "be more prepared" to elude investigators.
It is illegal for anyone on a temporary visa to work as a prostitute in New Zealand.
"We have to take steps to help ourselves because we know we are being targeted," the sex worker said.
Speaking on the condition of anonymity, she was paying a Chinese New Zealand resident to front for advertisements placed on adult websites and newspapers.
"People see her pictures on the website, but when clients book they will be sent to me or other girls who come from Korea," she said.
The sex worker said this was possible because "white people can't tell the difference" between one Asian sex worker to another.
"To the client, we all look the same," she said.
Advice had also been disseminated on a Korean chat app telling sex workers to avoid working in brothels in the wake of the raids, she said.
They were advised to operate from apartments or private residences instead.
"INZ can visit employers like brothels, but they cannot come into private homes to do random checks," she said.
"They need our full names and personal details and have proof of what we are doing."
Peter Devoy, INZ assistant general manager, said the agency received information regarding people working unlawfully in the sex industry from a variety of sources - including about advertisements on websites.
"Complaints that are made anonymously and contain information on people who are themselves using a fake name are notoriously difficult to pursue," Devoy said.
"INZ always works within the resources it has ... it will never be in a position where it can investigate 100 per cent of cases it becomes aware of."
Under current legislation, INZ must have good reasons that a named migrant who has breached their visa conditions would be present before entering a private residential address.
"As long as there are reasonable grounds to believe that the person named on the notice or order is present," Devoy said.
"Compliance officers may enter any premises, whether a brothel or private property, without a warrant in order to serve or execute a deportation liability notice or order."
"As long as there are reasonable grounds to believe that the person named on the notice or order is present."
Between December 2014 and March 2018, there had been 57 complaints to INZ about migrant sex workers.
Of the deportation cases in progress, two are holding visitor visas, one is out of the country and eight are unlawful in New Zealand.
"The remaining eight may be within their 42-day appeal period after being serviced a deportation liability notice," an INZ spokeswoman said.
"During this period they cannot be deported from the country unless they agree to waive their appeal rights."
A Korean-New Zealander sex worker, who also wanted to remain anonymous, said she was concerned about her illegal counterparts.
"The illegal sex workers don't know much about the law, I think they're a second victim (sic)," she said in a text to the Herald.
"They do the illegal service and set the price too low, we have to compete for customers. I think the illegal service is wrong."
She said the illegal prostitutes have an edge also because they were prepared to disregard health and safety rules and offered "extras".
"There are a lot of girls who think they can work with a temporary visa," she added.
Dame Catherine Healy, of the New Zealand Prostitutes Collective (NZPC), said most sex workers made their own arrangements with brothel owners.
"It would be unusual for a legal sex worker to front for another sex worker who doesn't have papers," she said.
Healy said NZPC has discussed concerns with INZ about sex workers who are working in breach of their temporary visas.
"These concerns relate to public health and the higher exposure these sex workers have to exploitation," she said.
"As well as the stigma of being deported potentially with sex work being explicitly referenced against their name online and on immigration records."
The sex worker deportation cases in progress comprise of three each from China and Taiwan, two from Hong Kong and the others from France, Malaysia and Russia.