The deceased was identified as Majibur Rahman, 70, son of late Gosai Sheikh.
ABM MehediMasud, officer-in-charge of Khoksha Police Station, said that Majibur’s grandson Nayem, 21, developed an illicit relationship with his maternal aunt Samia, 34, wife of Masud.
As Samia’s husband Masud went to Dhaka, Nayem came to his grandfather’s house on Sunday night and Majibur Rahman caught them red-handed.
Later, Nayem forcibly took his grandfather to courtyard of the house and hacked him with a sharp weapon,, leaving critically injured and fled the scene.
Later, the injured was taken to Khoksha Upazila Health Complex where doctors declared him dead.
On information, police recovered the body and arrested Nayeem.
Following his confessional statement, police also arrested Samia.