A builder has been given community service and fined £75,000 after work he carried out caused the death of an elderly couple from carbon monoxide poisoning.

Mohammed Jamil had been contracted to carry out work on the garage roof at the home of husband and wife Donald and Rosetta O'Sullivan in Leyton, between 14 February and 31 March 2009.

The Old Bailey heard last week (20 July) that Jamil was paid to raise the roof of the garage, but did not take into account the effect this would have on the safety of the gas appliances within the property.

An investigation by the Health & Safety Executive (HSE) found that in raising the roof, Jamil enclosed the flue of a boiler, leaving it in a dangerous and unsafe condition. As a result, the couple suffered carbon monoxide poisoning and were found dead at their home on 21 April 2009.

Had the flue not been enclosed, then the deaths could have been avoided.

Jamil, also from Leyton, pleaded guilty of breaching Regulation 8(1) of the Gas Safety (Installation & Use) Regulations 1998 for his failings in relation to the deaths. In addition to the £75,000 fine, he was ordered to pay £25,452 in costs and handed a 12-month community order requiring him to undertake 150 hours of community service.

After the hearing, HSE inspector Kevin Smith said: "This was a tragic incident that resulted in the unnecessary deaths of a retired couple in their own home as a result of carbon monoxide poisoning. Today's prosecution graphically illustrates the dangers of builders carrying out work without considering the effects on gas appliances. The builder failed to comply with the standards and regulations relating to gas fittings, which resulted in work that left flues in a dangerous condition, and allowed a colourless, odourless, silent killer to enter the property."

Paul Johnston, chief executive of Gas Safe Register, said: "In the right hands gas is safe, but badly fitted and poorly serviced gas appliances can cause gas leaks, fires, explosions and carbon monoxide poisoning."