Independent experts have tested food, water and air samples from the Steigenberger Aqua Magic hotel, where Cook agent Susan Cooper and her husband John died on August 21.

The examination included the hotel’s pool, carbon monoxide and carbon dioxide levels at the hotel, air conditioning units, and a “thorough audit of food storage, preparation, presentation and equipment”.

However, specialists were unable to access the Cooper’s hotel room, which has remained under the control of the Egyptian authorities due to their ongoing investigation.

Cook’s experts found:

• The examination of air and water quality came back clear.
• There was no evidence of carbon monoxide and there were normal carbon dioxide levels in the vicinity of the room.
• The tests on the swimming pools showed normal levels of chlorine.
• Food and hygiene standards identified "a high level of e-coli and staphylococcus bacteria".
• Tests did not identify the presence of shigella, listeria or salmonella.

Tests results were verified by a team at University College Hospitals in London, led by Dr Vanya Gant.

The operator said in a statement: “It is clear from these results something went wrong in August at the Steigenberger Aqua Magic Hotel in Hurghada and that standards fell below what we expect from our hotel partners.

“This is also supported by a review we have conducted of our customer satisfaction scores [at the Steigenberger Aqua Magic hotel], which fell sharply during this month.

"It is likely the presence of E. coli and staphylococcus would explain the raised level of illness reported among guests at the hotel during this time, supporting Thomas Cook’s decision to remove our 300 customers.

“However, neither our independent specialists nor Dr Vanya Gant believe that these results shed any light on the still unexplained cause of death of Mr and Mrs Cooper.

"We await the results of the autopsies being conducted by the Egyptian authorities.”