LA PORTE, Ind. (AP) — The parents of a LaPorte County girl with autism are accusing a special education teacher of belting the 8-year-old into a homemade restraining chair to subdue her in the classroom.

The (Northwest Indiana) Times reports that Charles and Heather Castle’s federal lawsuit filed June 29 alleges a teacher and two paraprofessionals at Kingsford Heights Elementary School used a restraining chair built by the teacher’s father.

The lawsuit alleges the LaPorte Community School Corp. violated its own policies regarding student restraint and never informed the parents their daughter was placed in the device.

The lawsuit says the Castles became suspicious after their daughter exhibited “new and troubling behaviors” at home, including emotional outbursts and refusal to wear a seat belt.

Superintendent Mark Francesconi didn’t respond Thursday to the newspaper’s request for comment.