A father and his 10-year-old son were barred from swimming at a U.K. sports center because they are not Muslims, the London Daily Mail reported Thursday.

The father, identified only as David T., told the newspaper that he and his son were stopped before going for a swim at the Clissold Leisure Centre in east London on Sunday morning.

What the father and son didn’t know was that the pool had been holding a "men-only modesty session" for Muslims at the time, one of several early morning get-togethers aimed at community groups with strict segregation rules, the Daily Mail reported.

"I asked whether my son and I could go as we were both male," David T. told the paper. "I was told that the session was for Muslims only and that we could not be admitted."

Red-faced managers at the complex said their staff was wrong to turn away the swimmers.

"The member of staff the user spoke with at the time was mistaken when referring to the session as Muslim only," a leisure center spokesman told the Daily Mail. "The men's modesty session is not a private [event] and is, therefore, open to the public. Muslim men and others can attend."

Click here to read more from the London Daily Mail.