The girl, a resident of Baselwa colony here, was raped by Anand Kumar, 46 and resident of the same locality, they said.
The victim's mother was an employee under Anand in his business and the accused used to visit their home frequently, police said.
The incident took place on January 25 when the girl was alone at her home. Taking advantage of the situation, Anand raped her and threatened her of dire consequences if she narrates the incident to anyone.
He raped her repeatedly for three months, police said, adding, the girl informed her grandparents recently.
The police have started investigations in the case, said Investigating officer ASI Raj Rani.