A case was registered on Tuesday on a complaint filed by the girl's mother. The accused was yet to be arrested.
The girl, a Class VI student, was allegedly sexually assaulted two weeks ago by the man, who works as a property dealer in the area.
He barged inside her house while her mother was away and sexually assaulted her. He threatened her with dire consequences if she revealed it to anyone, the police said.
It was after two weeks that the girl mustered the courage to inform her mother about it, they added.