A six-year-old girl, who was found dead in a forested area in Kanpur district of Uttar Pradesh on Sunday, was gang-raped, killed and her lungs were then taken out of the corpse by the killers, police said on Monday.
The lungs were removed to perform black magic, believing that it will help a woman give birth to a child, they said.
The girl had gone missing on the night of Diwali from the Ghatampur area.
The killers -- Ankul Kuril, 20, and Beeran, 31 -- who were arrested on Sunday, had removed her lungs and delivered those to key conspirator Parshuram Kuril to perform black magic, Additional Superintendent of Police (Rural) Brajesh Srivastava said.
Parshuram was arrested on Monday and his wife was also detained due to the apprehension that she knew about the incident, but did not talk about it to anyone, the officer added.
Parshuram initially tried to mislead the police, but facing intensive interrogation, broke down and confessed to his crime, the ASP said.
Parshuram told the police that he got married in 1999 but had not had a child so far, he said.
He persuaded his nephew, Ankul, and his friend Beeran, to kidnap the girl and remove her lungs, the ASP said.
Ankul and Beeran, who were heavily drunk, abducted the girl while she had gone out of her home in Bhadras village on Saturday night to buy firecrackers, he added.
They took her to a nearby jungle, where they raped the girl before killing her.
The accused have been charged under the Indian Penal Code (IPC) and the Protection of Children from Sexual Offences (POCSO) Act.
Kanpur's Deputy Inspector of General of Police Preetinder Singh had said forensic experts and sniffer dogs were pressed into service to gather scientific evidence to confirm if the girl was killed in an act of black magic.
The girl had gone missing on Saturday evening while her family was preparing for Diwali prayers.
The family looked for her in the nearby areas, including the jungle, using flashlights, but failed to locate her during the night, Singh had said, adding that her body was found by some villagers passing through the jungle on Sunday morning, the DIG said.
The girl's belongings, including her slippers and clothes, were found near a tree.
Uttar Pradesh Chief Minister Yogi Adityanath has taken note of the heinous crime and directed officials to take strict action against the accused.
He has also directed the officials to extend a financial help of Rs 5 lakh to the victim's family.
The chief minister has said the case would be heard in a fast-track court so that the accused are punished at the earliest.