An investigation by the Health and Safety Executive found Mansell Construction Services Ltd of Croydon and subcontractor Woodlands Plant Hire Ltd of Ickleton, South Cambridgeshire failed to properly manage asbestos during a flat refurbishment job in December 2009.

During the work in an occupied London Borough of Hackney block of flats, asbestos insulation board was disturbed and removed by unlicensed contractor, Woodlands Plant Hire Ltd, potentially releasing the deadly substance into the air.

A previous survey, identifying the presence of asbestos insulation board in a number of the properties, had been provided to Mansell, but had not been acted upon or passed to their subcontractors.

Mansell pleaded guilty and was fined £50,000 at the Old Bailey for breaching the Construction (Design and Management) Regulations.

Woodlands Plant Hire pleaded guilty of breaching the Control of Asbestos Regulations, and was fined £50,000. The companies were ordered to pay joint costs of £20,690.

HSE Inspector Dominic Ellis said: “Despite recent high profile campaigns on the dangers of working with asbestos, this case sadly illustrates some companies are still failing to manage the risks robustly.

“Mansell had information that asbestos was present, yet neglected to act on it, meaning a licensable asbestos material was removed in an uncontrolled manner, needlessly risking the health of contractors and members of the public.”