Police said the accused have confessed to the murder.
A headless body of a woman was found in Chamraha village here with four of her fingers missing, police said on Friday.
The woman, aged about 30-35 years, was only partially clothed and her head was found at some distance from her body, Superintendent of Police Ankur Agarwal said.
She was identified as Maya Devi, wife of Ramkumar Ahirwar, a resident of Pahra village of Chhatarpur district in Madhya Pradesh.
After a prima facie investigation, police made the family members suspects.
During interrogation, Ramkumar, the husband, his sons Suraj Prakash and Brijesh, and nephew Udaibhan, confessed to have hatched the plan for the woman's murder, the SP said.
According to Ramkumar's testimony, Maya Devi was his second wife, and had an illicit relationship with one of his sons and wanted to start a similar thing with the other son, Agarwal said.
Infuriated, the four took Maya Devi to Chamraha village in a vehicle, strangled her to death, and cut her head with an axe. They also cut four of her fingers.
The vehicle and axe used in crime have been recovered by the police, the SP said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)