Illegal rent-to-rent is on the increase, a bailiff has warned.

David Carter, who is managing director of eviction firm The Sheriffs Office, said that the practice is catching out both landlords and tenants.

Carter said that tenants find themselves out on the street, after thinking they had rented rooms in houses from legitimate landlords.

However, their rental agreement “is a lie”, he said.

He added: “Then look at the other side of the coin – the genuine landlord and actual property owner who finds that their tenant has sub-let their property out, room by room, to people they have never laid eyes on, let alone checked for references.

“We recently repossessed two adjacent properties for a landlord in Sutton, south London. He had let them out, not realising his two new tenants were actually husband and wife, because they were using different surnames.

“Once they had signed the tenancy agreements, they proceeded to sublet every room, often with a whole family in each room. The sub tenants all thought they had legitimate tenancies and were being given receipts for the rent – always payable in cash.

“Once the landlord found out, he obtained possession orders for both properties, which we enforced. The actual repossession took over eight hours, partly due to the sheer number of people living there, and also due to carloads of tenants’ friends and families turning up to try to stop what was happening, legitimately they thought.

“I feel a good deal of sympathy for the sub tenants – they had done nothing wrong but had been victims of this pair of ruthless and dishonest ‘fake landlords’ who were already wanted by the police.”

He said that immigrants in particular are being targeted by fake landlords.

He said that many are living in commercial premises without proper living facilities. In April, emergency services responding to a call about a small blaze found 100 people living in appalling conditions, with just one bathroom between them, in a building on a former industrial estate in Brent, north-west London.