Police recovered the bodies of a couple and their daughter from a rented house in the Rupayan Math area of Ashulia in Savar, on the outskirts of Dhaka, on Saturday night.
The deceased were identified as Sabur Mia, 26, son of Muzam Mia of Char Garuk Mandal village under Fulbari police station in Kurigram, his wife Rozina, 25, and their daughter Sumaiya, 09.
Police said the bodies of three members of the same family were recovered from Fazr Ali's house in the area around 10:00 pm. Sabur Mia was found hanging while the rest were on the bed.
Initially, it has been believed that Sabur Mia committed suicide after killing his wife and child.
Ashulia Police Station SI Al-Mamun said the motive behind their death could not be known yet.