Manoj Kumar, 25, was arrested in Bihar after the victim was discovered in his New Delhi apartment three days she had gone missing, The New York Times reported.
Doctors said they found an 8-inch bottle and several pieces of candle in her genitals. She had injuries to several parts of her body, including her lips, arms and anus, and bruise marks on her neck indicating attempts were made to strangle her.
The girl had gone missing April 14, and her parents reported her disappearance the next morning. The parents found her April 17 when they heard her crying.
Prime Minister Manmohan Singh called the act "shameful."
He had been criticized for a slow response to the December gang rape of a 23-year-old student on a bus, CNN reported. She died in a Singapore hospital, but her case led to strengthening of the country's rape laws.
The Indian legislature approved a bill in March increasing penalties for rape, gang rape and rape committed by public officials, and expanding the definition of rape. It raises the age of sexual consent to 18 and creates several new offenses, including stalking and voyeurism, but does not criminalize marital rape.
The new attack prompted BJP opposition leader Sushma Swaraj to demand the new law be amended to make sexual assaults on children and rapes involving brutality and barbarity punishable by death, The Times of India reported.