A Creekview High School teacher has been indicted by a Cherokee County grand jury after being arrested a month ago on charges of engaging in a four-month long relationship with a student.

Matthew Tamanini, 31, was indicted on one count of sexual assault against a person in custody, according to the grand jury February indictments released Feb. 13.

The Canton resident was initially charged with two counts of sexual assault of a person in custody following his Jan. 16 arrest after investigators with the Cherokee County Sheriff’s Office received information the drama and English teacher had a sexual relationship with a 16-year-old Creekview student, police said.

Tamanini, who was hired by the school district in May 2007, was reassigned to a non-school work site during the criminal investigation by the sheriff’s office, which was initiated by CCSD police the morning of Tamanini’s arrest, records show.

Tamanini resigned from the Cherokee County School District effective Jan. 31 citing “personal” as his reason for resignation, according to an agenda item approved during the Cherokee County Board of Education’s Feb. 7 meeting.

Lt. Jay Baker, spokesman with the Cherokee County Sheriff’s Office, said investigators believe the relationship had been going on for about four months.

“Investigators believe that the assaults occurred on the Creekview campus on at least two occasions,” Baker said at the time of the arrest.

District spokeswoman Barbara Jacoby said after the allegations came to light, Superintendent Dr. Frank Petruzielo authorized CCSD police to conduct an internal investigation Tuesday, Jan. 15, which prompted the school police to contact the sheriff’s office.