LISBON — Police have charged a teacher at a private religious school in Freeport with gross sexual assault.

On Friday, the Lisbon Police Department investigated a report that Derek Michael Boyce, 37, a teacher at Pine Tree Academy in Freeport, a Seventh-Day Adventist Christian school, was having a sexual relationship with a teenage female student at the school, according to court documents.

The Sagadahock County Sheriff’s Office took Boyce, who is married, into custody that day at his Woolwich home and transported him to the Androscoggin County Jail in Auburn after a police interview.

Since his arrest, Boyce has been charged with two counts of gross sexual assault and two counts of unlawful sexual contact with a minor, according to court documents. Each of the charges is punishable by up to five years in prison.

Boyce has remained at the jail on $50,000 bail with restrictions that he not have contact with the female, her family or anyone younger than 18, according to court documents.

In a sworn statement, a Lisbon detective wrote that the mother of the student came home Friday night to find her daughter naked and engaged in a sex act with Boyce in a dimly lit living room. The mother called police.

The mother had previously believed that Boyce, who was the girl’s math teacher, may have had an inappropriate relationship with the teen, according to police.

The girl told her mother she had had sexual intercourse with Boyce before.

Boyce told police his relationship began with the girl after she sustained a sports injury and had been depressed. They communicated over social media messaging applications.

The relationship became romantic in May, then turned sexual in July, he told police. They met in a park where they engaged in sex acts, Boyce said. They had sexual intercourse twice, he said.

Boyce told police the sexual contact was always consensual and that no drugs nor alcohol were involved.

Scott Christiansen, a spokesman for the school, issued a statement that said: “Mr. Boyce has been placed on administrative leave and has been instructed that he is not to be on campus or have student contact, pending the results of an investigation. Pine Tree Academy and the Northern New England Conference are cooperating with authorities as they investigate.”

Christiansen said the school believes this case is an isolated incident and that counselors have been made available to students, faculty and parents.

“As ever, the safety and well-being of our students is the highest priority of Pine Tree Academy,” he said.

“Rigorous background checks are conducted on all teachers during the hiring phase,” Christiansen said. “Background checks include all law-enforcement records, including traffic violations, as well as multiple interviews with references and previous employers. As a teacher at Pine Tree Academy, such a background check was done on Mr. Boyce.”

Boyce is scheduled to appear in court Dec. 5.

Derek Michael Boyce