CLIFTON, N.J. (CBSNewYork) — A New Jersey high school teacher has been arrested for allegedly having a sexual relationship with a 16-year-old student, prosecutors said Wednesday.

Detectives launched an investigation into the allegations on Monday, Passaic County Prosecutor Camelia Valdes said.

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1010 WINS’ Steve Sandberg reports

Investigators determined Kristin Leone, 26, who teaches history at Clifton High School, engaged in sexual conduct with the boy on at least two separate occasions — including one on school premises — Valdes said. The sexual conduct, prosecutors said, happened when the student got extra help in class after school.

On another occasion, investigators allege that Leone had sex with the student inside her home.

“While there is no evidence that she forced him physically, legally he cannot consent,” Valdes told CBS 2’s Christine Sloan.

Investigators said that the two began the inappropriate relationship with text messages. In a letter to parents, school officials said that a student and another teacher found out and alerted them, and then they contacted authorities.

Leone was arrested Monday and charged with sexual assault, endangering the welfare of a child, two counts of criminal sexual contact, luring and enticing a child, and two counts of official misconduct.

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She was released Monday night on $100,000 bail.

“We want every parent and student to know that we will continue to provide a safe and nurturing learning environment for all students at Clifton High School and all of the schools throughout the district,” Superintendent of Schools Richard Tardalo said in a statement.

Leone has been placed on leave from the district with pay, and instructed to remain off school property and to not have any contact with students.

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Parents and students expressed shock over the allegations.

“That’s nasty,” one girl said. “Why would a teacher want to sleep with a guy that’s 16? I think that’s really wrong.”

“It’s a little disturbing thinking about that — an older woman having relations with a young man,” a 15-year-old boy said. “The administration can do a better job of controlling the kids and the teachers. Make a line between them.”

“That’s disgusting, that’s unacceptable, that should never happen,” one parent said.

“She’s 26 years old,” another parent added. “She can’t find someone her own age?”

Clifton High School has had more than its share of sex scandals, 1010 WINS’ Steve Sandberg reports, and police have investigated other allegations at the school, such as students having sex under stairwells.

In the past year, at least three girls have claimed to having been raped or sexually assaulted by other students on campus.

In 2010, the former principal was accused of exposing himself to the mother of a special needs student during a meeting about her child.

The head of Passaic County’s Special Victims Unit said that more female teachers around the county are being charged with having sex with their students.

“It’s debatable whether that’s the  result of greater public awareness, or the fact that technology makes it easier to track down people,” Passaic County Chief Assistant Prosecutor Joseph Del Russo said.

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Leone faces up to 10 years in prison if convicted. The investigation is ongoing.