Over the past week, the Weekend Herald used a fake email account to reach out to five men who recently posted online advertisements to the North American-based website Craigslist offering free rent to young women in New Zealand.
The men all responded within a few hours, with one emailing that he wouldn't expect sex on the first night "as ud need to get used to me".
Under the pretence of entering one of these arrangements, two Herald reporters were invited into the downtown apartment of a man seeking a young woman to "have some real fun". The man, who works for a large multinational firm, posted the advertisement last month and said he had received four calls of interest.
He showed the Herald around the apartment and said an international student was currently sharing his king-sized bed; her belongings were in a suitcase on his bedroom floor.
The student had recently arrived in New Zealand, he said, and they were having "consensual" sex.
When asked if he expected sex in exchange for rent, the man said: "Sex is something which should be with the consent of both people. I never want anyone to use it as a payment, though I would love to go for this with a nice person.
"No one forces nothing on each other," said the man, whom the Herald has chosen not to identify.
Police, social agencies, student associations and cyber-safety groups are aware of women entering sex-for-rent deals with strangers, but said it was hard to know how prevalent this was because these exchanges occur behind closed doors.
Detective Senior Sergeant Glenn Baldwin, of Auckland's adult sexual assault unit, said his team was aware of cases where young women had unknowingly agreed to rental arrangements "which have turned out to be not exactly as they have expected or imagined".
A few of these cases were under active investigation, he said.
If continued accommodation was reliant on continued sexual contact, said police, this may create an imbalance in the relationship and the potential to lead to sexual assault where true consent was withdrawn.
Sex-for-rent was a "shocking" reality of the struggle students were facing in today's unaffordable rental market, Will Matthews, president of the Auckland University Students' Association, said.
Average weekly rent in Auckland hit $490 last year - an increase of more than $100 a week from 2010, according to government rental bond data analysed by Herald Insights.
"Students are getting more and more desperate and having to revert to measures such as rent-for-sex to be able to survive," Mr Matthews said.
Last year, a student living in a sex-for-rent arrangement applied to the association for a hardship grant, he said, adding that the number of hardship grant applications had more than doubled in the previous year (jumping from 41 to 96) largely because of accommodation woes.
Christchurch has faced a similar housing crisis since the deadly February 2011 earthquake and social agencies said sex-for-rent exchanges also occurred in the seedy underbelly of the city's rental market.
Maggy Tai Rakena, manager of START, a sexual abuse agency in Christchurch, said two teenagers recently fell behind in their rent and had sex with their landlord to wipe the debt after he suggested the deal.
They were 17 and 18.
As rental prices marched ever upward across the country, she said desperate tenants become willing to do "unusual and sad things".
Sarah-Jane Macmillan, service coordinator at Nelson's Sexual Abuse Support & Healing (SASH) centre, reported the organisation had recently seen an increase in young women being preyed on for sex-for-rent deals in backpackers and hostels.
Because of an extreme shortage in emergency accommodation for teenage women in Nelson, SASH has been forced to house sexual abuse victims at local backpackers - and in one case a predatory owner propositioned an 18-year-old victim for free food and board in exchange for sex, Macmillan said.
The teenager called for help and was immediately removed, but she told Ms Macmillan that six other young women she had befriended at the backpackers were living in sex-for-rent arrangements with the owner.
Police were contacted, Ms Macmillan said, but because the owner was not threatening or coercing the young women into sex no laws were being broken.
"It's a power imbalance that's happening here. This is preying on vulnerable young people who have nowhere else to go," Ms Macmillan said.
"What's their option: go sleep on the street or do this? There is no choice."
However, Catherine Healy, national co-ordinator of the New Zealand Prostitutes Collective, said it was not that black and white - some young women would be willingly entering sex-for-rent arrangements or actively seeking them out for the financial benefit.
For Ms Healy, the red flags in these types of exchanges centre around international women who may not understand the "nuances" in discreet advertisements.
One of the online ads posted on Craigslist specifically targeted international students. It read: "RENT IS FREE!!! Sincere and genuine middle aged, divorced guy living on North Shore seeking Asian female student to share 1 bedroom upmarket apartment."
Craigslist did not respond to several requests for comment. Netsafe chief technology officer Sean Lyons said it was not illegal to post a sex-for-rent ad or enter a sexual relationship on these grounds, but it could turn dangerous if parties were not clear about the expectations.
"The worrying element is people becoming duped into a situation where they think it's just free rent and then someone pressures or coerces or at worst physically forces themselves on to somebody under the guise of a perceived agreement," he said.
"If English is not your first language and you move here as a student and you read an advert that says in exchange for rent all they want is some fun, you might genuinely believe all they want is to play Scrabble."
When two strangers live together day-to-day, negotiating consent could become very difficult, Sandz Peipi Te Pou, national manager of Toah-nnest sexual violence prevention network, said.
"Our concern is that the power dynamic of someone paying the rent could put people in a position where it's hard to say 'no' to sex they don't want," Peipi Te Pou said.
"She can be threatened with eviction for not performing certain acts or she may find her personal space invaded, all justified by 'his version of the rules'."
Police urge anyone seeking accommodation, particularly from outside the city or even the country, to do as much background checking as possible before entering a rental arrangement.