The daughter of a British couple who died at an Egyptian resort hotel last week under mysterious circumstances said Sunday that she believes something in her parent's room killed them.

John and Susan Cooper died last Tuesday morning while on vacation at the Steigenberger Aqua Magic Hotel in the Egyptian Red Sea resort of Hurghada. The deaths of the couple, ages 69 and 63, prompted travel company Thomas Cook to evacuate 300 guests from the hotel as a precaution.

The couple's daughter, Kelly Ormerod, said she is suspicious because her parents had been in perfect health hours before they died. She told Sky News that her father, John Cooper died in his room while her mother died after she was taken to the hospital.

"I think when they went back to that room that evening there was something in that room that's actually killed them - whether they've inhaled something that poisoned them, I don't know," she told Sky News. "I can only have my opinion on what's gone on, but there's something that happened in that room that killed my parents."

On Sunday, Thomas Cook Group CEO Peter Fankhauser told Sky News the company has brought in experts to test food, water, and air conditioning systems at the Egyptian resort hotel.

"There is no evidence that it is a carbon monoxide poisoning. We have no evidence but I don't want to rule out anything before I really know the cause," he said.

Fankhauser told Sky News that experts have taken "probes of the food, of the hygienic systems, of water, as well as the air conditioning systems and all those probes are now in Egypt," and that tests should take 10 days to complete.

THOMAS COOK TAKES ITS GUESTS OUT OF EGYPT HOTEL AFTER 2 DIED

Besides the deaths of the couple, it has emerged that 13 other customers at the hotel had food poisoning. The hotel told The Associated Press in an email that there was no increased level of illness there and attributed the couple's deaths to "natural causes."

Prosecutors in Egypt on Saturday dismissed speculation that toxic gas fumes in the Coopers' hotel room killed the couple. An official inspection of the room found no harmful gas leaks and all the devices worked properly, they said.

The Egyptian prosecutor's office said it is awaiting a forensic analysis of samples taken from the bodies to provide more details, according to the AP.

Egyptian authorities dismissed criminal motives as being behind the deaths. An official statement by the Red Sea governorate on Friday said an initial medical examination of John Cooper showed he had suffered acute circulatory collapse and a sudden cardiac arrest. It said Susan Cooper later fainted and was rushed to a hospital, where resuscitation attempts continued for a half-hour.

The Associated Press contributed to this report.