Juliet Dennis and Amie Keeley

Investigations are continuing into the sudden deaths of a Thomas Cook travel agent and her husband on holiday in Egypt as industry professionals admit they are baffled by the tragedy.

Susan Cooper, 63, who worked at Cook’s Burnley branch, and husband John, 69, died last Tuesday (August 21). They were on a Cook holiday at the Steigenberger Aqua Magic hotel in the Red Sea resort of Hurghada.

Cook chief executive Peter Fankhauser has pledged to “get to the bottom” of the deaths following reports of an unusual smell in the couple’s room and speculation of legionnaire’s disease or carbon monoxide poisoning.

Cook said there was “no evidence” of carbon monoxide poisoning but described the circumstances around the deaths as “unclear”.

Test results on food, water and air conditioning are due to be released by the end of next week.

John Cooper died in his hotel room at 11am after a “sharp drop in blood circulation”, according to Egyptian authorities. His cause of death was listed as sudden heart and respiratory failure.

Susan Cooper was taken to hospital five hours later in a “state of fainting”. She was given heart recovery treatment for 30 minutes but died at around 5pm.

Egyptian investigators said there was no evidence of toxic gas emissions or leaks in the hotel room, while the Red Sea governorate said medical checks revealed “no criminal suspicions”.

The couple’s daughter, Kelly Ormerod, who was at the hotel and found her parents gravely ill, said she did not think her parents died from natural causes.

Professor Rodney Cartwright, a retired consultant microbiologist and former medical adviser to the travel industry, said: “For two people to die like this is very unusual. I’ve not seen a case like this before, where two people have died like this, apart from carbon monoxide poisoning. The most important thing is to put all the evidence together before jumping to any conclusions.”

An industry expert said Cook operated the most-stringent health and safety checks in the wake of the deaths of children Bobby and Christi Shepherd from carbon monoxide in Corfu 12 years ago.

He said: “They do audits in a way nobody else does, especially when it comes to carbon monoxide. They are almost obsessive about it because of the Corfu incident.”

Cook evacuated 301 customers from the Egyptian hotel as a “precautionary measure”. Of these, 225 were from the UK, of whom 118 opted to return home.

Customers with forward bookings are being offered alternative hotels at no extra cost or the option to cancel for the next four weeks.

A number of holidaymakers who stayed at the same hotel earlier in August have spoken to national media with complaints about contracting illnesses.

A Thomas Cook spokeswoman told The Times: “We are aware that a number of customers have come forward to say they have experienced illness while staying at the Steigenberger Aqua Magic Hotel.”

The company said it was contacting 150 hotel guests who had returned home in the past three days, plus a similar number who had been transferred to other hotels.