Meat was "undercooked" and hygiene was "a disgrace" at an Egyptian hotel where a British couple died, a woman who fell ill at the resort said.
Hotel guests have been returning to the UK after John Cooper, 69, and his wife Susan, 63, died in Hurghada last week.
Alison Cope stayed at the Steigenberger Aqua Magic at the same time as the couple and said "many people were ill".
The hotel said there was no evidence of an "increased incidence of illness", dismissing it as "rash speculations".
Mr and Mrs Cooper, from Burnley in Lancashire, died on Tuesday 21 August.
The Foreign and Commonwealth Office said it did not have any information yet about where and when a post-mortem examination would be carried out.
Following the deaths, Thomas Cook said it was removing all its customers and flew some holidaymakers back to the UK "as a precaution".
Ms Cope, 44, from Moseley in Birmingham, said: "The fish was raw in places and undercooked. The chicken had pink areas in it. You think, we don't want to eat that".
She said the "level of hygiene was a disgrace", with dirty cups, plates, knives and forks.
Ms Cope, who was among those who decided to fly home, said her two-week holiday at the hotel had been "a nightmare" and five out of seven of her family members were ill during their stay.
"My sister was getting very ill. Finding it hard to breathe, coughing up fluid, very weak and we just thought something's going on here and so contacted Thomas Cook many times."
She said "about 40 people" at the hotel were complaining of illness including "projectile vomiting and diarrhoea".
Other holidaymakers have told the BBC about their experiences with illness during stays at the hotel.
Janine Traviss, from Oldham, said she and her partner fell ill with a stomach bug and were "still recovering".
Chief executive of Thomas Cook, Peter Fankhauser, confirmed 13 customers had food poisoning but were not in a serious condition.
Dieter Geiger, general manager at Aqua Magic, said there was no evidence to support an "increased incidence of illness" at the hotel, which he dismissed as "rash speculations".
The couple's daughter, Kelly Ormerod, has insisted a strange odour in her parents' room had something to do with their deaths.
However, Egyptian investigators said on Saturday no traces of toxic gas had been detected.
Public prosecutor Nabil Sadeq confirmed all the installations were safe and the equipment was functioning without fault.
The tourism ministry said a medical examination showed Mr Cooper "experienced an extreme drop in the blood circulation and a sudden stop of the heart muscle".
The cause of Mrs Cooper's death was reported as a "halt of blood circulation and her respiratory functions".