Work visa holders moonlighting in part-time sex work are being denied entry to New Zealand.
In the 12 months to April, 45 foreigners holding valid working visas were refused entry for breaching their visa conditions, including working as prostitutes.
A North Shore International Academy graduate on a job search work visa was last month turned away at Auckland Airport after a baggage check found items used for sex work.
The Chinese woman, in her 20s, with qualifications to work as a chef, admitted to working part-time at a massage parlour in central Auckland.
Steve Stuart, intelligence risk and integrity general manager, said she was interviewed by the agency on May 21 upon her return from a holiday in China.
"Information obtained during the interview, together with items found in the passenger's luggage, indicated that the passenger had been working in New Zealand providing commercial sexual services and intended to continue doing so," he said.
Mr Stuart said that under the Immigration Act 2009, it is against the law for holders of temporary visas, such as student, work or visitor, to provide commercial sexual services while in the country.
"The passenger had also previously breached the conditions of her visa by studying in New Zealand for longer than three months without a student visa," he said.
"There was significant likelihood that the passenger would again breach her visa conditions and she was therefore denied entry."
Nearly one in four, or 24.5 per cent, of work visa holders who had been refused entry in the last year were China nationals.
Of the 45, three had held graduate job search visas, while others obtained work visas through partnership (six), working holiday (25), essential skills (three), specific purpose (seven) and one who was the partner of a worker.
A Chinese chef, whose visa was cancelled last year, said Immigration should be "sympathetic" to visa holders who did a second job.
The chef, also in her 20s, had worked in a Panmure brothel on her days off where she claimed she was paid upwards of $80 an hour, compared with $10 at the restaurant.
"There is a minimum wage in New Zealand, but the reality is that most migrant workers don't get paid that," said the chef, who did not want to be named.
"The only way we can pay our rent is to find a second job, and usually the only other work we can find is sex work."
She was keen to return to New Zealand, but was struggling to find a "good immigration adviser" to represent her.
Research on migrant sex workers by the Prostitutes Collective found nearly one in six were temporary visa holders.
These included 13 per cent who held a work visa, and 19 per cent on visitor or tourist visas.
More than a quarter, or 27 per cent, were international students.
The study also found that 86 per cent of migrant prostitutes here were from Asia.
Work visa holders between May 2012 and April 2013
45 refused entry to NZ
11 from China
4 from Ireland
3 from United Kingdom/Chile
(Source: Immigration New Zealand)