Following a complaint lodged by the girl's family, the headmaster was arrested yesterday and both the accused and the victim were sent for medical examination, said Inspector In-Charge of Kosagumuda police station D K Senapati.
Police said the headmaster used to call the girl to his room in the hostel premises on some pretext or the other and sexually abuse her.
"Though it was going on for quite some time, she could not muster courage to complain against the headmaster. On Tuesday, she told her parents about it and they lodged a complaint," the IIC said.