An investigation by the BBC has uncovered how vulnerable people are resorting to paying for a place to stay with sex.

The publication found numerous adverts online offering free rent in exchange for "services" and "company."

Sites such as Craigslist and Gumtree were found to have such deals, stating that "money is not an issue," but it will be a "mutual benefits arrangement" instead.

An ad for a room in Hull in the UK said: “Money is not an issue, I would prefer some company. There are some stipulations to the living arrangements which we would need to discuss directly.

“This would be a mutual benefits arrangement. Free rent, paid in other methods. Please contact me for more details."

However, other adverts come across more sinister, with one offering: "You agree [to] a couple of times a week, pop into my room sort of thing, " while another says, "I was thinking once a week, something like that, I'm happy as long as there's sex involved."

The investigation was launched after Centrepoint conducted a survey with 403 homeless people. The charity found that 25 per cent of those asked admitted to staying with a stranger.

One student told the BBC that she felt a "sex-for-rent" arrangement was her only option.

"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."

However, as awful as this is, it falls into a loophole where it's completely legal in the UK.

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."

Have you ever come across this in Ireland? The Centrepoint charity warned that the issued is widespread in the UK.