Fugro was principal contractor on a series of ground investigations, known as Package 16, on the project.

The Central Criminal Court heard that in February 2008, a Fugro employee was using a hydraulic breaker to create an inspection pit for a borehole outside 1 Hanover Street, London, when he struck a high voltage electric cable.

The employee, who was 63 at the time of the incident, suffered severe injuries as he was treated for 60% burns.

Safety inspectors found effective lines of communication were not established and appropriate training in safe digging techniques was not provided to operatives.

Key safety documentation showing the presence of the cable was not kept at the borehole location.

The site was scanned with a cable avoidance tool but no markings were made on the road to indicate where cables were found.

After the hearing HSE inspector Lisa Chappell said: “It is completely foreseeable that electric cables would be present in a busy London street, and there is well-established guidance and training to ensure digging is carried out safely.

“Had Fugro Engineering Services provided the correct training, supervision and a safe system of work, proportionate to the level of risk involved, then this serious incident could have been avoided.”

Fugro of Wallingford, Oxfordshire, had pleaded guilty at an earlier to safety breaches and was fined £55,000 and ordered to pay £30,000 in costs.