Cook agent Susan Cooper and her husband John fell fatally ill while staying at the Steigenberger Aqua Magic hotel in Hurghada last month.
In an official statement, Prosecutor Nabil Sadek said post-mortem examinations showed E. coli bacteria to be the cause of the death, the BBC reports.
The Evening Standard said the tests showed Mr Cooper suffered acute intestinal dysentery caused by E. coli, and Ms Cooper suffered Hemolytic-uremic syndrome (HUS), likely also because of E. coli.
Sadek added the couple’s bodies showed "no criminal violence" and other tests on air and water at the hotel found nothing unusual.
