However, expert witnesses said they could not be sure of the source of the poisonous gas that killed Susan Cooper, 63, and her husband John, 69, Blackburn Coroner’s Court heard.
Susan Cooper, who worked at a Thomas Cook agency in Burnley, was on holiday with her husband at the Aqua Magic Hotel in Hurghada when tragedy struck in August 2018.
A German tourist said there was a bed bug infestation in the room next door to the Coopers, which was treated with a pesticide, the BBC reports. The Coopers fell ill in the early hours and died the next day.
Home Office pathologist Dr Charles Wilson gave a cause of death for John Cooper as carbon monoxide toxicity and heart disease and carbon monoxide toxicity for Susan Cooper.
Toxicology expert professor Robert Chilcott told the inquest he detected the presence of carbon monoxide in blood samples from the bodies of the couple, but he couldn’t be certain of the levels.
Chilcott suggested in less developed countries, the pesticide used – Lambda – is sometimes diluted with another substance, dichloromethane, which causes the body to metabolise or ingest carbon monoxide.
A 10-hour exposure would be “sufficient to cause carbon monoxide poisoning”, he added.
Dr Nick Gent, a former senior medical adviser to Public Health England, agreed on the presence of carbon monoxide in the Coopers’ blood, but admitted he had no idea about the source.
When the Coopers failed to emerge for breakfast the next day, they were found seriously ill in their room by their daughter Kelly Ormerod.
The hearing has been adjourned until Friday (10 November).
