The Aqua Vale Swimming Pool remained open for 11 days even though environmental health chiefs raised concerns about a dangerous contamination.

Its two pools were later shut down, on April 3, after tests revealed that cryptosporidium was present in the water.

Parents are demanding answers from Everyone Active, the firm that runs the facility.

One father, whose six-year-old daughter had to visit the hospital after swimming there, said: “My daughter has been really ill for more than a week now after going swimming and we’ve been back and forward to the doctors and even up to the hospital she has been so bad.

“None of her friends and family who don’t swim there are sick and to hear they knew about it is infuriating.

“I’m considering taking her out of her lessons there now.”