Up to 40 people are believed to have been living in a three-bedroom house in Middlesex, in conditions described by the local council as 'dangerous'.
The situation was discovered following a raid by housing enforcement officers, which revealed 17 people living in the Edgware home and sharing one toilet – with Harrow Council stating they believe up to 40 people may have been living there prior to the raid.
Sharing news of the raid on its Twitter page, Harrow Council said 'no one should live like this' as it posted photographs of the crowded accommodation.
Inspectors said they could barely see the floor due to the number of mattresses crammed into the property – whose letting agent now faces prosecution from Harrow Council for renting out the home without a Multiple Occupancy Licence.
Cllr Graham Henson, cabinet member for environment, crime and community safety said in a statement: "It's troubling to see yet another case of overcrowding in Harrow. It's not safe, it's not sanitary and it exploits people who deserve somewhere decent to live, just like everyone else. Our licensing scheme is there to ensure incidents like this don't happen.
"While the majority of landlords and agents operate properly and safety, there are a few who think they can flout the rules. We are not afraid to take action – if we suspect foul play or wrongdoing we will carry out raids and will seek to prosecute."