The girl, resident of north Delhi's Kanjhawala, approached police Friday and lodged a complaint against two men, including her father.
"In her complaint, the girl said that her father and his friend raped her several times. She also claimed that she was threatened," said a police officer Sunday.
Her father was arrested after a medical examination of the girl.
"We have launched a search to nab the other man," said the officer.
The girl lived with her mother, who had lodged a complaint of domestic violence against her husband and was living separately for over four months.