A new breed of landlord that demands sex from tenants instead of rent has emerged in south-east England.
Vulnerable young people, typically female, are being targeted by predatory homeowners, typically male, who wish to capitalise on the UK housing crisis in the most predatory way imaginable.
The BBC spoke to people on both sides of this nefarious corner of the rental market and examined hundreds of online classified adverts relating to it.
A female student told them she was left with no choice but to take up a "sex-for-rent" offer from a landlord because she was desperate to find somewhere to live.
She said: "He took me into his living room, got me drinks, and then after that it was just straight upstairs and go for it.
"He would do what he wanted to do, forcefully, and I just sort of went along with it – after the third time, I started feeling physically unwell."
The practice has become so widespread that the BBC claim to have seen over 100 adverts on classified website Craigslist offering "rent-for-sex" type deals.
In 2015 an IBTimes UK special report into the London rent crisis found similar disturbing adverts. One of them read: "I am looking for a slutty girl who wants to stay rent free in central London (zone 1) at my house in exchange for nsa [no strings attached sex]."
A landlord engaged in a "rent-for-sex" arrangement defended his actions, telling the BBC: "You can argue that high rent charged by landlords is taking advantage too. There's no compulsion for them to do this. Everyone goes into it with their eyes wide open.
"I am the last type of person who'd like to take advantage. Both sides have something the other person wants. I see it as a win-win situation," he added.
More people were in need of council homes than ever before. The stock of affordable housing has shrunk as tenants have been offered the right to buy their council and housing association properties.
Meanwhile, average rents in the private sector have continued to rise as wages have stagnated in the last decade. The result is a UK housing crisis that politicians on all sides have acknowledged.
The practice of "sex-for-rent" is thought to be legal while coming very close to breaching prostitution laws.
Andrew Wallis, of anti-slavery charity Unseen, said: "I think these adverts go as close to the edge of the law that they possibly can without breaking the law.
"They would argue that they have chosen voluntarily to enter that situation. The trouble is when you have a vulnerable person who then becomes exploited, the concept of choice soon disappears."
Labour MP Peter Kyle is demanding that UK legislation is updated to outlaw the practice.