More than 20 men were discovered living together in "slum-like conditions" at a three-bed semi-detached home in Kingsbury on Thursday morning (September 27).
Mattresses lined the walls of the illegally-leased Brent home where 26 tenants are believed to have paid up to £50 a week to live in appalling conditions.
Brent Council housing officers raided the Princes Avenue addresses at dawn following complaint from neighbours about a number of men seen coming and going from the home.
Pictures taken by officers at the raid show every inch of the home, including the illegally converted, windowless loft, had been turned into sleeping spaces.
The bathroom was piled high with dirty shoes and clothes, food was left out in the kitchen to rot and empty beer cans and rubbish was strewn throughout the property.
As well as being dangerously dirty the home failed to comply with basic safety standards with faulty smoke alarms, poor ventilation and fire hazards.
Following the raid Brent Council has launched an investigation to track down the alleged rogue landlord or agent renting out the property.
Cabinet Member for Housing and Welfare Reform, Councillor Eleanor Southwood, said: "We have a zero tolerance policy against landlords who exploit tenants by housing them in slum-like conditions. "
She added: "No tenant in Brent should believe that they are powerless against a landlord who takes their money in exchange for squalor. We are here to help tenants fight back against rogue landlords by taking them to court."
From October 1 any Brent property rented out to five or more people who are not all related will require a mandatory licence.