A hotel room in Egypt where a British couple died was next door to a room that had been sprayed with chemicals to kill bed bugs only hours before their deaths, an inquest has heard.
John Cooper, 69, and his wife Susan, 63, from Burnley in Lancashire died on 21 August 2018 in the Egyptian resort of Hurghada at the Steigenberger Aqua Magic Hotel.
The couple died from neither carbon monoxide nor food poisoning, according to an earlier report, which added they could have been caused by possible exposure to an "infectious biological agent or toxic chemicals".
On the first day of a two-day inquest hearing in Burnley, a German tourist said in a statement he reported a bed bug infestation in the room next door - which had a locked, adjoining door.
It was treated the next day with Lambda, a pesticide.
The Coopers' daughter, Kelly Ormerod, a HMRC civil servant, said her parents were fit and healthy for their age and had been enjoying a "brilliant" holiday with her, their three grandchildren, and family friends.
Her mother, who was a cashier at Thomas Cook, had visited the same hotel in April that year, describing it as "fabulous", and wanted to take the whole family back.
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On the evening of 20 August, they all went to the hotel's restaurant and a bar, before heading in for the night.
Ms Ormerod's daughter, Molly, who was then aged 12, was staying on a single bed in the Coopers' room, which she said had a "yeasty smell". At 1am, Mr Cooper rang to say she was feeling unwell and took her back to her mother's room upstairs.
Mr and Mrs Cooper were not at breakfast the next day, and Ms Ormerod discovered they were seriously ill, saying her father came to the door and said "I really don't feel well" while retching.
She told the hearing her mother was in bed, "groaning", with vomit in her hair and around the room, where she noticed a strange "heavy" smell.
Two doctors were summoned, but Ms Ormerod said they were in "panic mode", as her parents appeared to get worse and her father struggled to breathe.
Ms Ormerod added: "His eyes kind of... a glazed, staring look."
Mr Cooper was declared dead on the hotel room floor, while Mrs Cooper was taken to a clinic at the hotel where she was said to be "super agitated" and delirious, the inquest was told.
Mrs Cooper was taken to hospital in an ambulance but died at 4.12pm.
Both were repatriated to the UK in sealed, zinc-lined coffins.
A statement from Dominik Bibi, from Germany, who arrived in the early hours of 20 August, said his mother-in-law was booked to stay in room 5106 - next door to the Coopers.
His statement added: "On entering I immediately noticed a funny smell, like that of mould or damp.
"There was a lot of bed bugs in the bed and under it."
He added a cleaner and manager came and apologised, while his mother-in-law took his room further down the corridor.
Mr Bibi said around lunchtime he was outside her room when he saw three men, one of whom was holding a pesticide canister he assumed was being used to get rid of bedbugs.
He added after around five or 10 minutes they left the room, and used masking tape to seal the room.
"I would not say the job was very professional," Mr Bibi's statement continued, adding the air conditioning at the hotel was not working that day, and a cleaner told the family work was being done on the system.
He also said he and other family members were unwell, but he expected that during a holiday in Egypt.
The inquest continues.