Cherry Knoll Elementary School Principal Chris Parker noticed the coach exit the gym last week. Parker said he went inside to make sure someone was watching the team.
Parker saw the coach's husband passing basketballs to the team as they practiced free throws.
Parker checked the online sex offender registry, which indicates the man has a 2002 conviction for third-degree criminal sexual conduct.
Traverse City Area Public Schools Superintendent Stephen Cousins said district officials filed a report so the Grand Traverse County Sheriff's Department can determine if the incident violated state law.