A policeman reportedly killed his pregnant wife and later dismembered her in an attempt to hide the murder evidence in Sarankhola upazila of Bagerhat.
The incident took place on Thursday night.
Murdered Josna Begum, 35, of Changaon village in Rupsha upazila of Khulna, was nearly seven months pregnant.
Law enforcement arrested Saddam Hossain, a constable of Tafalbari police outpost, from his home adjacent to the outpost.
Saddam who is from Satkhira, confessed to the murder during primary interrogation, said Sarankhola police station Officer-in-Charge (OC) (Investigation), Md Mafizur Rahman.
The OC gave a grisly description of the incident based on Saddam's confession.
Saddam strangled his wife to death following a family feud and dismembered the body to dump it somewhere to conceal the murder, he said.
He severed her head and both wrists, cutting her belly open and taking out her now dead baby, Mafizur said.
Acting on a tipoff, police raided his house and retrieved the body parts from a bag, the OC said.
Murder charges will be brought against the policeman, he added.