Thomas Cook faces compensation claims from dozens of customers struck down by severe vomiting and diarrhoea at a five-star all-inclusive resort in Turkey.
The operator has suspended holidays to the Sentido Perissia Hotel in Side after some guests had to be hospitalised and others were confined to their rooms.
According to a report on MailOnline, guests complained of undercooked food and poor hygiene at the resort.
It said lawyers believe problems at the hotel were going on for nearly a month.
Thomas Cook has arranged for an independent UK hygiene consultant to carry out a comprehensive review of the hotel.
"Preliminary indications suggest the outbreak was of a viral nature," it said.
"The hotel has put in place a number of preventative measures to minimise any further illness. Our team in resort are providing assistance to our guests and we will continue to closely monitor the situation.
"As a precautionary measure only, new arrivals up to and including 2 September 2013 will have their holiday in alternative accommodation. We sincerely apologise for the inconvenience caused."
But some sick customers complained to the MailOnline that the operator had refused to fly them home.
Others said the operator had told them they were the only people suffering with the illness but they had later found out there were many more.
One said her daughter was projectile vomiting so severe "it was like something out of the Exorcist".
She said seven members of her group had been hospitalised over nine days.
According to reports, hotel staff closed down the swimming pool for two days last week as they tried to deal with the outbreak.
