A Gwinnett County high school teacher has resigned amid allegations she had an inappropriate relationship with one of her students, a district spokeswoman confirmed to AJC.com on Tuesday.

In a letter sent to parents Tuesday morning, Archer High School principal Ken Johnson said a police investigation was launched after school officials learned of the alleged relationship between a high school senior and a teacher at the school.

“On Monday we received a report about this situation and our school immediately contacted the police and the school district's Division of Human Resources,” Johnson wrote. “As this has been and continues to be an active police investigation there are not many details I can share. However, I can tell you that the teacher has resigned from Gwinnett County Public Schools and the school system will be forwarding information about these allegations to the Professional Standards Commission.”

Gwinnett schools spokeswoman Sloan Roach confirmed that the teacher resigned Monday. Her name has not been released.

The student’s mother told Channel 2 Action News that off-campus tutoring turned to sex between her 17-year-old son and his physical education teacher, who she said is 25.

She said the two had sex at least three times since October, including once at the student’s home while she was at work.

Gwinnett police spokeswoman Cpl. Michele Pihera declined to say if an arrest has been made in the case.

In his letter, Johnson called the alleged inappropriate behavior between the teacher and student unacceptable.

“While this is not a situation we have experienced at our school previously, one time is too many,” he said. “Ethics matter, and the trust our community places in its educators matters to Archer and to Gwinnett County Public Schools. This is not something we take for granted.”

The investigation is the latest in a string of sexual relationships between educators and students in the state’s largest school district.

In December, a former South Gwinnett High School band director pleaded guilty to sexually abusing four students in less than three years on the job. Villie Jones pleaded to 20 charges of sexual assault by a person with supervisory or disciplinary authority and was sentenced to 10 years in prison and 20 years of probation.

And in 2017, former Parkview High teacher and Georgia Bulldogs receiver Michael “Mikey” Henderson was arrested on sexual assault charges after authorities discovered he had a sexual relationship with a student in his geometry class that lasted more than two years.

According to police, Henderson had between 20 and 30 sexual encounters with the student, all of which occurred on school grounds. He pleaded guilty and was sentenced to five years in prison and 15 on probation.

In other news: 

Henry County police were attempting to pull over a stolen Mazda CX9 on I-75 north around 2 a.m. The Mazda got off exit 222 on Jodeco Road, turned around and re-entered the northbound lanes traveling south, officials said.