A coach at a center in Iowa that has trained Olympic champions is facing allegations that he abused young female gymnasts and secretly photographed others undressing at a prior job in Mississippi.

A former gymnastics coach who was first accused of abuse more than three years ago has been arrested on federal child porn charges. Sean Gardner, 38, made his first court appearance Friday on a charge of producing visual depictions of minors engaging in sexually explicit conduct.

Sean Gardner is facing federal charges for child pornography, alleging he used a hidden camera to record underage gymnasts in Mississippi.