It comes after a London landlord was fined following the poisoning of ten people, who inhaled carbon monoxide from a faulty boiler near their three flats.

The boiler had not been serviced by a CORGI-registered engineer for 20 years. Landlords are legally required to obtain an annual certificate of maintenance from a CORGI-registered specialist.

A Health and Safety Executive (HSE) spokesman said:

"Landlords need to realise that they can potentially face charges of manslaughter if they fail in their duties and someone is killed as a result".