Paul Alker, 33, of Brynteg, was working for Wrexham Roofing Services, when he stepped on a roof light and fell around 25 feet onto the store floor.

His employer, Steven Christopher Smith, director of Wrexham Roof Services Ltd, Rhostyllen, Wrexham, was jailed for two and a half years in November 2007 in relation to this incident.

He pleaded guilty to manslaughter, a charge under the Health and Safety at Work etc Act 1974 and a further charge of committing acts intending to pervert the course of justice.

Comet Group was prosecuted by the Health and Safety Executive following the incident on 7 June 2007. The company, which is registered at George Street in Hull, pleaded guilty to a charge under Section 3(1) of the Health and Safety at Work etc Act 1974 and was also ordered to pay £24,446 in costs.

Mr Alker was not wearing any equipment which could have prevented his fall. He suffered multiple injuries including rib fractures, a broken collar bone and soft tissue injuries which led to a fatal pulmonary embolism on 12 June 2007.

Following the hearing, HSE inspector Debbie John said: “Comet failed to ensure that its contractor had taken steps to prevent falls through the fragile roof lights, ultimately leading to the death of a worker.

“This incident could have been avoided if the roof lights at the Wrexham store had been protected and Mr Alker had been provided with appropriate safety equipment.

“The law is clear: companies must ensure contractors are competent to do the work they are hired to do, and they need to understand their responsibilities.

“A safe system of work must be agreed and the company should monitor contractors to make sure they undertake work safely as agreed. My thoughts are with the family at this difficult time.”