The 17-year-old was injured at the 368-homes Sniperley Park DH1 homes development on Thursday afternoon.

The force said his head and neck injuries were “life-threatening” and he had been taken to the Royal Victoria Infirmary in Newcastle.

The Bellway Homes site is currently at the groundworks stage with Esh Group carrying out preparatory work.

Esh said the incident involved an employee of a subcontractor.

It told the BBC: “The entire company is deeply saddened by this event, and communication and efforts to assist the police and HSE have been ongoing from the outset and throughout,” a spokesperson said.

“First and foremost, our thoughts are with the injured person, their family and friends, and we will continue to assist and provide support where appropriate.”

A spokesperson for Bellway, said: “We are aware of an incident at our DH1 development involving a contractor working for the principal contractor.

“Our thoughts are with the contractor, his family, friends and colleagues at this time.”