According to a report filed with the East Ridge Police Department, Grant Blaylock, 52, exchanged nude photos with a student via text messages over the course of two years and repeatedly touched her private parts.
The young woman told Principal Tammy Helton in December that she and Blaylock got involved in 2013 and continued until she graduated in 2014, according to the report.
During that time, the student performed oral sex on Blaylock in a locked room inside his classroom, the report states.
The Times Free Press does not identify juveniles or victims of alleged sex crimes under most circumstances.
The report was filed with the East Ridge Police Department, but the investigation has been transferred to the sheriff's office.
Officials with the Hamilton County Department of Education wouldn't say if Blaylock still works in the school system, and Helton didn't respond to a request for comment Friday. The December police report said Blaylock was still teaching at East Ridge High School, and he is listed as a teacher on the school's website.
Blaylock was arrested on a charge of aggravated domestic assault on Sept. 30 after his wife accused him of hitting her in the face with a cellphone.
Blaylock was suspended without pay until the charges were dismissed months later, after his wife declined to press charges.
Bill Speek, Blaylock's attorney, said last fall his client's wife was the only witness, and she testified he tossed a cellphone behind him and it hit her.
Speek said he had no comment on behalf of his client about the current investigation.
Blaylock also was arrested in Hamilton County in 1997 and 1998 on assault charges.
Contact staff writer Kendi Anderson at kendi.anderson@timesfreepress.com or 423-757-6592.