The BBC claims that a lettings agency has been demanding hundreds of pounds in payment before prospective tenants are allowed to view properties for rent.
The BBC accuses Flintons lettings agency in London of the act, and says it may be illegal.
The agency denies any wrongdoing.
The Victoria Derbyshire programme on BBC Two says Israel Kujore and his friend Harry responded to one of Flintons's adverts.
“He said they had gone to see an agent who had told them they needed to pay a deposit to see a room but that the money would be refundable” says a BBC report.
“They had paid £300 each to see a property, but Israel soon realised something was wrong” it continues.
The BBC also quotes Labour’s housing spokeswoman Melanie Onn calling for the government to give greater protection to renters.
"Letting agents as well as landlords should be properly regulated," she said.
"Of the 8,000 letting agents we've got around the country, only about half of those are voluntarily signed up to a code that means that they will operate to the highest professional standards. That means that half of them are not."
You can see a BBC Online report of the story here.