The accused has been identified as Nanak, a resident of Bharat Nagar in north west Delhi, police said.
"The accused was arrested after we received a complaint from the parents of the girl last (Monday) night," a senior police officer told IANS.
"In their complaint, the parents alleged that the girl was repeatedly raped by the accused for the last three to four months," he added.
The family of the girl resides in the rented flat of the accused.
"The girl first narrated her ordeal to her mother some ten days back and then on Janmashtami when I asked her about it she told me about the incident," the girl's father told IANS.
The father further alleged that his daughter was raped by the accused whenever she arrived early from her school.
A case was registered against the accused under section 376 (rape) of the Indian Penal Code and POCSO (Protection of Children from Sexual Offences) Act, police said.
