The incident occurred at Chandrabhan village under Mahua police station after 30-year-old Kaushal Kumar of Kanhauli village, under the same police station, went to his in-laws' place.
Stating that Kaushal was married to Reena Kumari in February, his family members alleged that she was having an affair with her elder sister's husband, they said.
They have also alleged that Kaushal was called to his in-laws' place and then murdered, police said.
Meanwhile, police have arrested five persons -- his wife, parents-in-law and brothers-in-law and further probing the case.
The dead body has been sent for postmortem.