The accused Ramesh Kodi (28) has been arrested after the victim's family lodged an FIR against him, they said.
According to police, Kodi, a tractor driver, was known to her family. On December 29, he picked up the girl from her house in a village near here on the pretext of offering her some work.
However, he took the victim to a place called Dhoka Mardi, about 8 km from here, and sexually assaulted her, police said, adding Kodi threatened the minor with dire consequences if she revealed the incident to anyone.
As the girl's father was not in the town the family did not report the matter to police. They approached police on his arrival and lodged a complaint against Kodi.