The Enquirer understands that Competition & Markets Authority officials raided the offices of a leading demolition specialist.

An industry source said: “The officers locked-down every computer in the head office.

“Everyone in the office was ordered to freeze and not touch their computers while the entire server and IT system was downloaded by the authority.”

Six demolition contractors are understood to have come under the spotlight of the CMA since it launched a probe into possible collusion in the supply of construction services in Britain in March.

Investigators have declined to identify the specific sector or scale of the inquiry.

But multiple industry sources have confirmed it involves the demolition industry.

One leading industry source said: “This investigation is centred on the demolition sector.

“There is a lot of nervousness around about this because the CMA is not shy about handing out big fines if they find any evidence of wrongdoing.”

The CMA was originally hoping to make an announcement on the progress of the investigation by the end of September but that deadline has now been extended.