Judge Justice Field, said the ground testing firm, which the court had heard was in financial difficulty, could pay the fine over 10 years at £38,500 a year.

He said the gross breach of its duty to the young soil engineer was a grave offence.

Justice Field said the fine marked the gravity of the crime and the deterrent effect it would have on companies to comply with health and safety laws.

He said a larger fine would cause the small scale company to be liquidated, and four people would lose their jobs.

“It may well be that the fine in the terms of its payment will put this company into liquidation. If that is the case it’s unfortunate but unavoidable but it’s a consequence of the serious breach,” he said.

No-one was in the dock during the three-week trial as the director of the company Peter Eaton, 61, is seriously ill and unable to stand trial.

Imperial College graduate Wright had worked for Cotswold Geotechnical for two years.

The court heard that Wright had been left to work alone in an unshored 3.5 metre-deep trench to ‘finish-up’ after the company director had decided to leave for the day.

The two people who owned the development plot decided to stay at the site as they knew Wright was working alone in the trench. About 15 minutes later they heard a muffled noise and then a shout for help.

While one of the men called the emergency services, the other one ran to the trench where he saw earth had fallen in and buried Wright up to his head.

He climbed into the trench and removed some of the earth to enable the young geologist to breathe. But more earth fell into the pit covering the geologist completely. Wright died of traumatic asphyxiation.