A prep school mathematics teacher in North Carolina has been arrested after police alleged she had inappropriate sexual contact with three male students.

Authorities said the investigation began after school officials reported the claims.

Erin Elizabeth McAuliffe, 25, faces three counts of sexual activity with a student and one count of indecent liberties with a minor. WNCN reported she is due to appear in Nash County District Court on Monday.

McAuliffe previously taught at Rocky Mount Preparatory School. School officials said she last worked there on May 4, which was one day before staff contacted police about the allegations.

Police said the alleged incidents occurred off campus. They involved two students who were 17 years old and one student who was 16 years old at the time.

School administrators said they have cooperated with the investigation. In a statement, they said they had worked fully with law enforcement as officers handled the matter.

McAuliffe was taken into custody and later released from the Carteret County Jail. WNCN reported she posted a $20,000 bond.

A former student who graduated last year said the accusations caused shock among former classmates. Dayvon Steel told WNCN that the allegations were disturbing.

“It’s very shocking and appalling that a person would do that with a student,” Steel said.

WITN reported that a phone number listed for McAuliffe has been disconnected. It is not clear whether she has hired a lawyer.

According to her LinkedIn profile, McAuliffe earned a bachelor’s degree in mathematics from Methodist University.