Workers have reportedly been living on a construction site in Abercorn Estate in St John’s Wood.

Maida Vale local Murad Qureshi said that he saw mattresses and clothing on the building site. He contacted construction union Unite to alert them.

Unite regional officer Paul Lomax visited Warner House, one of three blocks on the estate, where work is being done on the basement.

He observed a green sofa, clothes hung on a washing line, mattresses and food containers at the site. Neighbours in Warner House have confirmed seeing clothes hung out to dry.

“Workers must never be allowed to live on a construction site, the potential for serious injury is huge and there are also massive occupational health issues that need to be considered,” said Mr Lomax.

Mr Qureshi also alerted the Health and Safety Executive (HSE). “It’s the kind of stuff you see in the developing world,” he said. “Health and safety regulations have been developed for a reason in this country. It’s the kind of thing we have to guard against.”

A HSE spokesperson said: “HSE has visited the Warner House site twice recently. The first occasion was as part of our campaign of inspection visits in London. During this visit a prohibition notice was served preventing all work on site, other enforcement action to address safety management matters was also taken.

“The second visit was made on June 4 in direct response to a complaint. Inspectors found no evidence of workers sleeping on site at either visit. Further follow-up work with the principal contractor will be taking place.”

Mr Lomax also wrote to Westminster City Council with his findings. According to an email seen by the Wood and Vale, the council has no powers to control work practice on the site. “We only enforce the building regulations, which set standards for construction. Clearly the enforcing authority in this instance is the HSE,” said Julian Tanton, Head of Building Control at the council.

Geoff Barraclough, Labour councillor for Maida Vale, said: “These reports are very worrying if true. Construction workers do a critical job in London and don’t deserve to be exploited by penny-pinching developers.”

The freehold of Warner House is owned by a private company, Kunta Kinte Ltd. Its two main shareholders, both of whom are registered at 7 Bradman House on the estate, were unavailable for comment.