An Indian teenager cut off a man's penis after he allegedly tried to rape her for a second time.

The 17-year-old girl from the northern state of Bihar was defending herself against the unwanted sexual advances of Mahendra Mehta, a local "tantric healer" who is also reportedly her uncle.

Her courage has been praised by police who are still hunting Mehta, 35, who was reportedly sent to the girl's home by her family to 'cure' her after she fell ill.

According to the Times of India, Mehta diagnosed her as being demonically possessed before taking her to an isolated room where he tried to sexually assault her. When she protested he allegedly gagged and raped her on 1 July.

The following day, he asked her to come to his house but she was armed with a sharp knife and a mobile. She castrated him while recording his conversations before managing to escape, the paper reported.

Senior officer AK Singh said Mehta had not tried to heal the girl, but had instead abused his position as a member of the family and her trust.

The girl had complained to her local village council but was unable to deal with the incident.

Singh, who is superintendent at the Alam Nagar police station, located around 200 miles east of the state capital, Patna, told The Independent: "The incident happened 20 days ago. Initially the girl went to the [village council] but when that was unable to resolve the matter the case was brought to me. We then filed a case at the women's police station."

Latest figures reveal 478 reported rapes occurred in the first five months of this year in Bihar, with 130 rapes in May alone.

The offence comes just weeks after a seven-year-old girl allegedly was raped by her neighbour, also a tantric, in West Bengal.