According to a report in Times of India, the incident took place on July 2 but came to light on July 30 when an FIR was lodged with the all-woman police station in Madhepura, sources said.
The girl had fallen sick at home on July 1. Her mother seeked her sister's husband Mahendra Mehta's help who was known for practicing tantrik.
On receiving message, Mehta came to help the girl. He took the girl to an isolated room in his house telling that she was under the influence of some supernatural power.
There he tried to sexually assault her. When she protested, he allegedly gagged and raped her.
Mehta was a close family relative so no one suspected his real intentions. The girl also did not say anything, sources said.
The tantrik visited the girl the next day when her mother was away and asked her to come to his house, police said.
The girl visited him on July 2 night armed with a sharp knife and cellphone. While his conversations were recorded on her cellphone, she castrated him. Though the tantrik tried to stop her she managed to wriggle out and escaped, police said.
She then approached the police with her family but they tried to hush it up, sources said.
An FIR was finally lodged with mahila police station at Madhepura on July 30 after some political leaders intervened.
The girl was also sent for a medical examination.
