Michael Bury, a member at The Hydro, took his son for a 30 minute swimming session at the pool yesterday, October 23.
But on arrival, Michael was asked to pay another Â£1 for his son, who was subject to chargeable entry due to his age.
Michael said: "I didn't have any money on me except my locker Â£1 which was old. My son was very excited about getting in the swimming pool and already had his arm-bands on.
"The lady behind the desk said I couldn't go in - I told her that by the time I get home and get a new Â£1 I would miss the session and asked her if I could pay with a new one tomorrow as I go there five times a week.
"She said 'no'. She then asked her manager. Her manager said 'no'. I said can I leave my membership card and pay tomorrow, she still said 'no'.
"My toddler was still very excited, waiting to go in and I didn't want to upset him. I told them I'm going in regardless. When I changed to enter the pool the lifeguards had shut the gate to stop me from going in. I explained what had happened to them, they thought it was ridiculous and let me through.
"My toddler was so happy in the pool, but then the manager re-appeared and told me if I didn't get out of the pool she would phone the police.
"Fortunately, by the time we had our full half-an-hour in the pool and left, my son and I hadn't been arrested over an old Â£1."
Now, regular member Michael has expressed concern that he may be banned from using The Hydro facilities as a result of the incident.
But Harrogate Borough Council, which owns The Hydro has apologised for any 'misunderstanding'.
A spokesperson for Harrogate Borough Council said: "The council operates an admissions and charging policy across all of its sport and leisure facilities.
"In cases such as this the site would normally attempt to make arrangements to collect payment at a later point in order to maintain our high levels of customer satisfaction.
“We’re sorry if there has been a misunderstanding, and would urge the customer to get in touch with us to discuss the matter further.”