London landlords advised on breaking letting law
Companies like Airbnb have transformed the tourism industry by making it easy for people to rent out their homes to visitors.
But in London, hosts are legally restricted to renting out their homes for more than 90 nights a year - unless they get council planning permission.
An undercover investigation by BBC London has found large management companies are advising landlords on how to break the 90-night limit.
You can see this story in full on BBC Inside Out London at 19:30 BST on BBC One on Monday 24 February, or via iPlayer for seven days afterwards.