An Arkansas assistant principal resigned from a middle school over allegations that she was in a sexual relationship with a student.

Jessica Williams was arrested Monday after police received a tip claiming she had an ongoing relationship with a Waldron School District student, news station KFSM reported.

Police said the district received an anonymous letter accusing the administrator of misconduct with a 16-year-old male student.

Investigators interviewed the teen who admitted that he started having sex with Williams in early summer. He also claimed that the two exchanged explicit photos.

In a police interview, Williams reportedly confessed to having sexual encounters with the teen on several occasions.

She was booked at Scott County Detention Center on charges of sexual assault and tampering with evidence. Her bond was set Tuesday at $100,000.