Blackstone Properties Management, and its director Mohamed Ali Rasool, were fined a total of £480,000 plus costs at Westminster Magistrate Court.
It followed a dawn raid at a property in Hyde Park Gate in 2021 by council officers, where a 22-bedroom house of multiple occupation was found to have multiple fire and damp risks.
The landlord had previously been warned that they needed to apply for a licence for the property, while complaints about the safety of the property had been raised by a tenant in 2020.
The investigation found defective and damaged fire doors, as well as covered fire alarms and burnt out electrical sockets.
The lack of proper kitchen facilities meant that tenants had resorted to cooking in their rooms using camping-style facilities, while there was rising damp and mould growth throughout the property. The inside of the property was found to be so damp that mushrooms were growing in the upper floors.
Councillor Cem Kemahli, lead member for planning and public realm at Kensington and Chelsea Council, said this judgement was a clear lesson to other landlords and agents that they will be prosecuted if they are found to be delivering substandard accommodation.
He continued: “We want the best homes in the Royal Borough of Kensington and Chelsea. Our landlord licensing schemes are seeking out the bad operators to ensure safer homes for everyone and a fairer market for good operators.
“Privately rented homes form a crucial part of our housing mix but they must be up to scratch. Our teams stand by to help and assist landlords in answering concerns or offering suggestions about how to improve your properties.”