According to police, the mother of the class 10th girl, who is a student of a school at Badagan in the district, lodged a complaint against a youth on Saturday accusing him of having raped her daughter.
The youth is a distant relative of the girl, inspector in-charge of Baliguda police station Yasawant Hial said quoting the complaint lodged by the girl's mother.
"The girl was apparently reluctant to reveal the matter earlier due to fear," police said, adding that the school authorities came to know about the pregnancy during a routine health check-up last week.
The headmaster and the district collector have been informed about the matter and efforts are on to trace the accused, who is stated to be working in Kerala, police said.
A committee has been formed by the collector to inquire into the incident.