An outbreak of illness at a four-star Egypt holiday resort is said to have left dozens of Brits bed-ridden and many on drips.
Some holidaymakers said poor hygeine was to blame for the complaints at Coral Sea Water World in Sharm el Sheikh.
Lawyers are saying they expected more than 100 to have been brought down by the bug.
Nick Harris of law firm Simpson Millar told ITV News "at least 50" Brits have already been in contact having come down with the illness and says the company is expecting more than double that number again.
He said some had complained of being confined to their bedrooms with a drip to aid recovery.
Extra doctors are thought to have been brought in to deal with the high number of cases.
One holidaymaker wrote on TripAdvisor that the resort had been visited by hygeine inspectors during their trip last month, prompting staff to start wearing surgical gloves.
Another said she saw her husband spending his 30th birthday being "violently sick" after falling foul of a mystery illness.
Lynne Norman wrote on Trip Advisor that she suffered "crippling cramps and fever" due to the virus.
Lawyers say many of those that fell ill have been diagnosed with Shigella - an illness that can cause symptoms such as diarrhea, fever and stomach cramps, as well as large and painful bowel movements.
The illness can last for weeks in some cases.
First Choice, which is the exclusive travel agent for the resort, said it was "aware of a small number of cases of sickness at the Coral Sea Water World, Egypt with symptoms similar to a virus."
Staff at Coral Sea Water World have not responded to ITV News requests for comment by the time of publication.
Five-year-old Chloe Johnson from London drowned in a swimming pool at the resort last year.