A former Pacelli High School teacher is accused of sexually abusing a male student at the school.

Police Chief Brian Krueger said Mary Gilles, 28, was arrested for third-degree criminal sexual conduct on Monday afternoon at her home after police were summoned to Pacelli that morning. She was taken to the Mower County Jail and is awaiting formal charges.

Krueger would not provide more details on the case. The Mower County Attorney’s office also declined to comment on Gilles’s charges.

Gilles taught eighth- through 12th-grade math. Pacelli officials released a statement Tuesday confirming the school notified the police after staff discovered potentially suspicious behavior. Gilles was fired from Pacelli on Tuesday.

“It’s an unfortunate, unfortunate thing, and very painful for the school, and for the community,” said Joel Hennessy, director of communications for the Diocese of Winona.

Krueger said the case is under investigation.

Correction: An earlier edition of this post stated Gilles was arrested at Pacelli. She was arrested at her home.