A young man was discovered living in a “coffin-like” gas meter cupboard under the stairs by inspectors during a council raid.

The tenant, who slept in the unventilated space measuring one metre by two metres, was one of 12 people found occupying an overcrowded house in Beckton, Newham.

Officers also discovered bunk beds crammed into single rooms, plus fire and electrical safety hazards during the early-morning visit attended by mayor of Newham Sir Robin Wales and housing officers.

He said: “It cannot be right in the 21st century, in one of the world’s wealthiest cities, a young man is being forced to pay hundreds of pounds to rent a cupboard under the stairs, sleeping alongside the gas meter.”

Sir Robin spearheaded a private licensing scheme to crack down on rogue landlords which is currently under threat from being scrapped by the government.

He said “The scenes we saw on this visit are a timely reminder that, while by tackling bad landlords we are driving up standards, there is still much to do.

“That is why it’s imperative that the government allow us to continue with this work, and stop the exploitation of tenants.”

At another overcrowded property in Upton Park, three people were found each paying £200 a month to live in a shed structure.

The rest of the property had been split into eight rooms, over three floors, and were being shared by four families.

The landlords will be served with financial penalty notices (FPNs), that in the worst-case scenerio could see them being ordered to pay a fee of £30,000.

GMB leaders Warren Kenny and Tim Roache, who were invited along, also expressed disgust at the desperate conditions.

Tim Roache, the trade union’s general secretary said: “Our visit to Newham was a real eye-opener, we all know the housing market is broken, but finding people living in cupboards marks a new low.”

“It’s fantastic to see how Newham’s licensing scheme is forcing this kind of chronic exploitation of tenants into the light, and how its effective enforcement by dedicated workers on the front line is bring the guilty landlords to book.”