For Rent: Rooms Under the Radar

The rental market is thriving on the surface - but behind closed doors and in back streets, a black-market housing crisis is spreading. Thousands of people across London are thought to be living in unlicensed Houses in Multiple Occupation (HMOs) - properties where three or more unrelated people share bathrooms and kitchens. Many of these HMOs fall under licensing schemes designed to ensure safety and proper management, yet remain unlicensed and unregulated for years.

Reporter Tarah Welsh meets tenants living in overcrowded and illegal homes - including those without contracts, privacy or proper facilities. She hears from a man who lived in a two-bed flat with 20 others where a fatal fire broke out, and from a family of four squeezed into one room in another property. Digging deeper, she uncovers how some landlords are profiting while breaking the law.

Some stretched councils are struggling to enforce the rules, even when serious breaches are reported. Why are potentially thousands of illegal HMOs undetected by the authorities, and what are the implications for residents?