A British couple died in Egypt from carbon monoxide poisoning after the next-door hotel room was sprayed with pesticide to kill bedbugs, an inquest has ruled.
John Cooper and Susan Cooper, from Lancashire, fell ill while on a family holiday in Hurghada on 21 August 2018.
An inquest heard the next-door room had been fumigated following a report of a bedbug infestation.
James Adeley, senior coroner said the couple were poisoned overnight.
Mr Cooper, 69, and his wife, 63, had been enjoying a "brilliant" holiday while staying at the Steigenberger Aqua Magic Hotel, Preston Coroner's Court heard.
But around lunch time on the eighth day into their holiday the room next to theirs, which had an adjoining locked door between them, was fumigated with pesticide, known as Lambda, for a bedbug infestation.
The room was then sealed with masking tape around the door.
Hours later the couple returned to their room for the night but were found seriously ill the next day by their daughter, Kelly Ormerod.
Mr Cooper, a builder, was declared dead in the room and Mrs Cooper, a cashier in a Thomas Cook bureau de change, hours later in hospital.
The inquest heard in some countries the pesticide Lambda is sometimes diluted with another substance, dichloromethane, which causes the body to metabolise or ingest carbon monoxide.
Following a three-day inquest hearing, Dr James Adeley, senior coroner for Lancashire, ruled the deaths, on 21 August 2018, were caused by carbon monoxide poisoning as a result of inhaling the vapour from spraying the pesticide which contained dichloromethane.
At the time of their deaths, Thomas Cook removed all of its customers from the hotel.
'Answers we deserve'
The inquest, five years on, also heard of multiple, repeated attempts to obtain more documents and information from the authorities in Egypt despite numerous requests from the Foreign Office.
Dr Adeley said Mr Cooper's illness and death was rapid, but described the medical treatment provided for Mrs Cooper as "utterly insufficient" after she was taken to a clinic in the hotel before an ambulance was called, creating a delay of four hours before she got to hospital.
Ms Ormerod said "after more than five years of waiting, we've finally been given some closure around the deaths of mum and dad".
"Our family still struggle to comprehend what we went through that day and feel like it should never have happened," she said.
"The last few years have been the most traumatic time for all of us.
"Having to relive everything at the inquest has been harrowing but it was something we had to do for mum and dad.
"We'd do anything to have them back in our lives but we take some small comfort from at least having the answers we deserve."