At least 30 children were reportedly rushed to hospital with a vomiting illness from a Spanish holiday report.
Children who played in the pool at the Marina Parc hotel in Arenal D'en Castell, Menorca, experienced "severe sickness and diarrhoea".
The issue is now going through legal proceedings, holiday claims specialists Simpson Millar Solicitors confirmed.
Kevin Kiernan, who is dad to a 10-month-old baby girl, was one of the parents who has spoken out about the outbreak.
"One minute [my daughter] was smiling and laughing then she was violently sick it was very scary," he told The Mirror.
"Then when we cleaned her up but she was sick again. We were really worried.”
Kiernan and his partner Sarah were at the resort for a two-week holiday.
He claimed they were given a "dirty cot" in the room and waitresses were "failing" to clean the highchairs.
On a Facebook status by Kiernan on 14 May, he wrote: "The pool is dirty with confirmed algae scum floating on the surface.
"My 10-month-old baby among 21 other children (number still rising) have been taken to hospital for five days with a gastrointestinal infection either from the pool or restaurant."
Kiernan said the following day after seeing the "scum" in the pool, his daughter was "projectile vomiting".
She was taken to hospital and put on a drip. While the family were there, they met other parents whose children were sick from the same resort.
Kiernan's daughter was discharged after four days, but then had to return back to the hospital for further tests.
The family flew home five days early from their holiday and their daughter was treated in Cardiff hospital.
The dad claims First Choice, the holiday company who organised the holiday to this resort, offered him a £50 travel voucher after he complained.
When contacted by The Huffington Post UK, a spokesman for First Choice said: "We are sorry to hear of the Kiernan family’s experience. As this is now subject to legal proceedings, it would be inappropriate for us to comment further.
"We closely audit all resorts to which we operate to ensure that health, hygiene and comfort levels are maintained in line with industry standards."
The Huffington Post UK has contacted Marina Parc Hotel for further comment.