LANCASTER -- A teacher at Lancaster High School has resigned after inappropriate behavior was brought to the administration's attention.

The district says a student told a staff member on Friday, June 2, that a male teacher had recently sent him inappropriate text messages. That teacher was sent to Human Resources and immediately placed on leave, the district says.

The following Monday, the teacher came back to Human Resources and resigned.

The investigation is ongoing, the district says, and Child Protective Services has been notified. The Texas Education Agency and law enforcement officials have also been informed.

"As educators, we have the obligation to protect our students and learning community," the district said. "We hold the teaching profession in high regard and we strive to always be models. The nature of this adult’s communication was inappropriate, unprofessional and will not be tolerated in Lancaster ISD."