Inquests are to open later on Tuesday into the deaths of a British couple at a hotel in Egypt on a Thomas Cook holiday.
John and Susan Cooper, from Burnley, Lancashire, died on August 21 after becoming suddenly ill while staying at the Steigenberger Aqua Magic Hotel in the Red Sea resort of Hurghada.
The authorities in Egypt have said their forensic examinations showed the deaths were linked to E.coli bacteria.
The findings have been disputed by the couple's daughter, Kelly Ormerod.
Subsequent post-mortem examinations carried out in the UK have not been able to find out the cause of death and more tests are being carried out, but the results could take some time to come back.
The Egyptian authorities said their examinations showed Mr Cooper, 69, suffered acute intestinal dysentery caused by E.coli and Mrs Cooper, a 63-year-old Thomas Cook employee, suffered a complication linked to infection, likely to have been caused by E.coli.
Ms Ormerod, 40, who was on holiday with her parents and her own three children at the time, has said E.coli does not explain the rapid nature of her mother and father's sudden death.
The family have said they hope the coroner's investigation will establish the "true cause" of death.
Thomas Cook's own tests identified a high level of E.coli at the hotel, which would "explain the raised level of illness reported among guests".
However, the firm said the independent specialists it commissioned to carry out the tests, and Dr Vanya Gant from University College London
Hospitals NHS Foundation Trust, did not believe the results "shed any light" on the cause of the Coopers' deaths.
Thomas Cook moved 300 guests out of the hotel 24 hours after the couple died as a precaution.
The inquests are expected to be opened and adjourned around midday at Preston Coroner's Court.