A mother and her three children were found dead at their house in the capital's Turag area early yesterday.
Police suspected the housewife committed suicide after strangling her children due to financial hardship.
The dead are Rehena Parvin, 35, her daughters Nusrat, 13, and Arisha, 9, and son Saad, aged about nine months.
Police recovered the bodies from Rehena's house around 2:00am and sent those to Dhaka Medical College (DMC) for autopsies.
Mahbub-e-Khuda, officer-in-charge of Turag Police Station, said Rehana's body was hanging from the ceiling fan of a room and the bodies of her children were on a bed, with their necks tied with separate scarfs.
According to neighbours, Rehana's husband Mostafa Kamal used to work for a buying house in Chittagong and was also involved in a multi-level marketing business. Recently he became unemployed and was facing a financial crisis.
Talking to reporters at the DMC, Mostafa said two influential men, who had taken Tk 50 lakh from him to invest the amount in a multi-level marketing business, were not repaying the money. Instead, they were threatening him.
He suspected the two might have been behind the deaths of his wife and children. He, however, didn't disclose the two names.
Mostafa returned home around 12:15am and found the room locked from inside. He extended his hand through a window to the cleat of the door and managed to open it, only to find the four dead, neighbours told The Daily Star quoting Mostafa as saying.
Sharif Khan, who lives next to Mostafa's room, said he heard Shanta complaining about food during iftar on Thursday.
Mostafa's family lived in three rooms and his mother and sister in three others. Ten more rooms on the plot were rented out to tenants, said neighbours.
Rehana's cousin Nur Hossain said Mostafa and Rehana used to collect rent from tenants, but Mostafa's mother and a sister took over off late. The couple was also asked to leave the house.
Kafil Uddin, a neighbour of the victims, said he heard Mostafa screaming around 12:30am yesterday. Soon he went to the room and found the four dead.
Mostafa with the help of several others got the hanging body down.
Autopsies were carried out on the four bodies at the DMC. Sohel Mahmud, chief of the forensic medicine department at the medical college, said three children were strangulated to death.
The reason for their mother's death would be ascertained after examining some tissues of her body, he added.
OC Mahbub said they would investigate further to find out the reason for the deaths. “We are looking into all the aspects, including a land dispute, multi-level marketing business and financial crisis.”
He said Rehana's brother Shamsur Rahman filed a murder case, accusing Mostafa and his sister Kohinur.