A married couple have been fined £65,970 for renting out unsafe property.
The two-story house in Roman Road, Ilford, had been illegally converted into five studio flats, with no alarm system or fire escape routes, exposed electrics and water leaks.
Rana Mohammed Irfan and his wife Naheed Rana Irfan, from De Vere Gardens, Ilford, have to pay within five months, or face an 18 month prison sentence.
Redbridge council said it is their record fine under the Housing Act 2004 and one of the highest fines for Housing Act offences in the country.
This case is part of a crackdown by the council on unscrupulous landlords in the borough, with another landlord being fined £19,000 last month.
The property was visited on several occasions between July 2012 and January 2014 by the council, and at Snaresbrook Crown Court on July 24 this year, each landlord was ordered to pay £32,985 after pleading guilty.