Officers on duty at the Mirzapur village in Jhalakathi were 'shocked and surprised' when mother-of-three Monju Begum turned up to report she had been raped.
According to Mrs Begum, 40, her neighbour Mozammel Haq Mazi burst into her home and assaulted her.
But, fighting back, the woman overpowered Mr Mazi and said she had chopped off his penis to teach him a lesson.
She told local officers she had then popped it in a bag to prove to police it was him who had committed the crime.
The dramatic conclusion came, Ms Begum claims, after six months of harassment by Mr Mazi.
But - speaking from hospital where he was being treated for his injuries - Mr Mazi denied he was at fault and claimed he had been attacked after Ms Begun flew into a jealous rage.
'We were having an affair and recently she suggested that both of us can go and settle down in Dhaka,' he told the BBC.
'I refused and told her I cannot leave my wife and children, so she took revenge on me.'
Police spokesman Abul Khaer said that a rape complaint has been made and that Mr Mazi, a married father of five, would be arrested once he is released from hospital which is in nearby Barisal.
'She has registered a case accusing him of attempted rape,' he said.
'It is quite an unusual incident. As far as I am aware, this is the first time that a woman has brought a severed penis to the police station as evidence.
'She said she fought back and cut off his penis and brought it to our police station in a polythene bag to prove that Mr Mazi tried to rape her.'
For those of you brave enough to have read this far, doctors working to re-attach Mr Mazi's manhood have confirmed his organ could not be reattached and is no longer in use.
'We are treating him so that he can urinate normally without the penis,' Prof AMSM Sharfuzzaman, a senior surgeon at the Sher-e-Bangla Medical College and Hospital, added.