ANDOVER (CBS) — A former New Hampshire state representative has filed a federal lawsuit accusing her former Phillips Academy professor of sexually abusing her when she was a student at the school.

Marie Sapienza, a four-term member of the New Hampshire House, says she was a 15-year-old day student at the academy when she alleges Alexander Theroux sexually abused her around 1982.

She said she never graduated because of the trauma caused by Theroux.

“The instance of the abuse was followed by phone calls to my home,” she said. “I was offered the equivalent of an A to take one of Alexander Theroux’s classes. He did subsequently leave the school.”

Sapienza also claims she told the then-headmaster about the abuse, but that he did nothing.

“Donald McNamar, who was the headmaster, asked to meet with me and I agreed to do that,” Sapienza said. “I told him about what happened to me, and he basically said, ‘It doesn’t matter, I’m not going to do anything, he’s not here anymore.'”

She and attorney Mitchell Garabedian are filing a suit against Theroux for $20 million.

“This was a criminal act,” said Garabedian. “This is not consenting adults–this is a person in a position of trust, a teacher, who sexually abused a student, age 15, teacher was an adult. The student reports it to the school newspaper, the newspaper reports it to the headmaster, and the headmaster covers it up.”

Thoreau published a book in 1981 about an affair between a teacher and a student, entitled “Darconville’s Cat.”

WBZ NewsRadio 1030’s Karyn Regal reports