A 24-year-old man, who is pursuing chartered accountancy, was arrested for the rape of his five-year-old neighbour in east Delhi's Mandawali area on Friday evening, police said.
The accused, identified as Sunil Kumar, had been living in Ganesh Nagar area.
The police said the minor lived with her divorced mother and was playing outside her house when the accused approached her and lured her into his rented accommodation.
The police arrested Kumar after the minor mother lodged a police complaint.
Police said the accused locked the room as soon as the girl entered and then raped her. Stricken with fear at the prospect of being arrested, he then threatened the victim and told her that he would kill her as well as her mother if she told anyone about the incident.
But the girl told her mother when she got back home and she was taken to a hospital where medical examination confirmed sexual assault, the officer said.
The accused was arrested within hours of the rape.