The girl suffered from extensive internal injuries and has been admitted to All India Institute Of Medical Science or AIIMS in Delhi, said the Delhi Commission for Women or DCW in a statement.
The police has registered a case and arrested the stepfather.
"The girl's condition is very serious. Her private parts are infected with pus and according to the doctors, she will have to undergo a surgery. Taking note of the seriousness of the crime, the judge appointed for this case reached AIIMS to record the minor's statement," said the DCW statement.
The incident came to light after a woman in the child's neighborhood saw her bleeding and informed the DCW on its 181 women helpline.
The accused had married the girl's mother a year ago.
In her statement, the girl said that the accused took her to his workplace and sexually assaulted her. She alleged that he beat her up and threatened to kill her if she told anyone about the incident, reported the Press Trust of India.
DCW members visited the child at AIIMS and counselled her.
"The father said he committed the gruesome act under the influence of alcohol. He is a caretaker of a house in Saket. He had sexually assaulted her couple of days ago too," it further added.
DCW chairperson Swati Maliwal demanded that the accused person be hanged immediately.
With PTI Inputs
Get the latest election news, live updates and election schedule for Lok Sabha Elections 2019 on ndtv.com/elections. Like us on Facebook or follow us on Twitter and Instagram for updates from each of the 543 parliamentary seats for the 2019 Indian general elections.