Brighton Police say an investigation has confirmed that a woman who was working as a teacher at McQuaid Jesuit High School had an inappropriate relationship with a 17-year-old student in 2016.
Police Chief Mark Henderson says McQuaid learned about the misconduct last month and contacted police.
The investigation found the relationship was consensual and the District Attorney's office says it could not be prosecuted because the student was of legal age, and the statute of limitations for endangering a child had expired.
Police don't believe other students are involved. McQuaid says the woman no longer works for the school.