E.coli has been found at the Egyptian hotel where a Burnley couple died but this does not establish the cause of their deaths, tour operator Thomas Cook said.

The firm commissioned tests of food, water and air at the Steigenberger Aqua Magic Hotel in the Red Sea resort of Hurghada after John and Susan Cooper, who were both in their sixties, died on August 21.

The tests on the food and hygiene standards identified a high level of e.coli and staphylococcus bacteria, the company said in a statement.

But neither the independent specialists who carried out the investigation nor a medical expert "believe that these results shed any light on the still unexplained cause of death of Mr and Mrs Cooper", according to Thomas Cook.

Chief executive Peter Fankhauser said: "Everyone at Thomas Cook is deeply saddened by the tragic deaths of John and Susan Cooper while staying at the Steigenberger Aqua Magic Hotel in Hurghada. Susan was a longstanding and much-loved colleague of ours.

"We continue to await the results of the investigation being conducted by the Egyptian authorities and are working closely with the Foreign and Commonwealth Office to ensure we prioritise the very best interests of the Cooper family.

"However, the tests that Thomas Cook commissioned show that hygiene at the Steigenberger Aqua Magic Hotel during the month of August did not meet the standards we expect. I am very sorry for all our customers who fell ill while on a Thomas Cook holiday at this hotel.

"These results, while not establishing the cause of the tragic deaths of John and Susan Cooper, have prompted us to commit further resource to tackle hygiene standards in those hotels where we identify a higher than average level of sickness.

"At any one time, Thomas Cook has more than 500,000 people holidaying with us somewhere in the world. We will continue to do all that we can to keep them safe and well on what should be the happiest weeks of their year."

The Lancashire Telegraph reported on Tuesday the story of Rishton sisters Melissa Nuttall, 29, and Anne Marie McCaffrey, 33, who cut short their 14-night stay at the Steigenberger Aqua Magic Hotel in July after they both fell cripplingly ill with painful stomach cramps, vomiting and diarrhoea and say they are still showing signs of salmonella.