A family of slum landlords who crammed 31 people into a suburban four-bedroom house has been ordered to pay back almost £250,000 under the Proceeds of Crime Act.

The landlords were earning more than £100,000 a year from the enterprise, which involved squeezing tenants on “sleeping shifts” into rooms fitted with up to four beds each in a house in Wembley, north London. Some tenants were made to sleep in an improvised shed built in the back garden made from wood offcuts, pallets and tarpaulin.

A judge at Harrow crown court ordered Harsha Shah and her daughter, Chandni Shah, to pay £116,000 in a confiscation order. Jaydipkumar Valand, who was acting as their agent and rent collector at the Napier Road property, was subjected to a £5,000 order.

Sanjay Shah, Harsha Shah’s brother, was sentenced with his sister and niece to pay £41,000 in fines. All the defendants were ordered to pay £82,367 in costs.

The property was ruled to be an illegal house of multiple occupation after a 2016 raid by a London Borough of Brent housing enforcement officer. They were found guilty of breaching landlord licensing rules in May 2017.

“We will use every legal power we have to come down hard on landlords and agents who exploit tenants in Brent,” said councillor Eleanor Southwood, the cabinet member for housing and welfare reform. “Every house in multiple occupation needs a licence, which helps to create decent living standards in the borough. We will track down landlords who do not licence their properties and rip off tenants by housing them in miserable conditions.”

Vispasp Sarkari, 56, another landlord in the area, was fined last year for squeezing 27 people into a four-bedroom semi-detached house that had been converted into seven tiny flats. He was ordered last month to pay a record £1.5m penalty for breaking planning laws on that and other properties which he had illegally converted into bedsits. One of the properties where families were found paying £650 a month was infested with cockroaches, rats and damp.

The government has estimated that there are more than 10,000 rogue landlords operating nationwide, many of whom own England’s 500,000 houses of multiple occupation.

The government announced new rules last year under which rooms slept in by one adult will have to be no smaller than 6.5 square metres (70 square feet), and those slept in by two adults 10.2 square metres. Rooms slept in by children of 10 years and younger will have to be no smaller than 4.6 square metres.