The arrested is Yusuf Chow-kider,35, who allegedly killed his father Abdul Ali Chowkider,65, step mother Habia Begum,40, and step sister Tahmina,20.

According to his confessional statement, police recovered bloodstained clothes and sharp weapon used in murder from a ditch behind the house of the 'killer's' father-in- law.

Earlier, police detained Yusuf's mother-in-law Rizia Begum,50, sister-in-law Minara Begum,35, and brother-in-law Kamal Mridha,26, for interrogation.

Yusuf slaughtered his father, step mother and step sister over a land dispute at Krishnapur village of Dacua union in Galachipa on May 23.