The 32-year-old woman reportedly used a sickle to cut off his genitals.
The woman had been living with her brother-in-law as her husband was working more than 1100km away in another city.
She allegedly faked consent of intercourse and when he forced himself onto her she reached for a sickle and severed his penis, the Times of India reported.
She then took his penis to the police station as evidence.
Police from the Sidhi district of Madhya Pradesh attempted to send medical support to the man, but he had reportedly committed suicide.
The woman then told police that this was the only way to stop him attacking her and that she had no regrets, the Times of India reported.
"This is a rare case and has to be investigated for a proper charge sheet," said Sidhi police spokesman Abid Khan.