A retired schoolteacher, his wife, daughter and son were found dead in a locked house in Rangpur city late last night.

The bodies were recovered around 11:30pm from the Daspara (Machhuapara) area of the city, said Nazmul Kader, officer-in-charge of Rangpur Metropolitan Kotwali Police Station.

The deceased were identified as retired Rangpur Zilla School teacher Ganapati Chakraborty, 65; his wife, Pritilata Chakraborty, 50; their daughter, Agami Chakraborty Prarthi, 23; and son, Priyam Chakraborty, 12.

Subir Chowdhury, in-charge of Rangpur Metropolitan CID, told The Daily Star that the bodies of the mother and daughter were recovered from the staircase, while the father’s body was found on the roof.

The body of his son was found under a bed, he added.

“The household belongings were found scattered and in disarray. For now, it appears to be a robbery. However, nothing can be confirmed until the investigation is completed,” he said.

Sanatan Chakrabarty, deputy commissioner of Rangpur Metropolitan Police and head of the Detective Branch, said the bodies were sent to the morgue of Rangpur Medical College Hospital for autopsies.

“Initially, we suspect that they were strangled,” he said, adding that the killings may have taken place at any time between midnight on Thursday and early Friday.

Police, CID and DB teams have launched a joint investigation into the killings, OC Nazmul said.

According to locals, Ganapati retired from Rangpur Zilla School on December 31 last year. His daughter completed her master's degree in English from Rangpur Carmichael College this year, while his son was a Class 5 student at Rangpur Zilla School.

Puja Chakraborty, Pritilata's younger sister, told The Daily Star that she last spoke to her sister on Thursday afternoon. All four mobile phones used by the family had been switched off since Thursday night.

"We came to Daspara on Saturday night after finding their phones switched off. The main gate of the house was locked and all the lights inside were off. Police later arrived, broke the lock and entered the house, where they recovered the bodies," she said.

"I cannot understand who killed my sister and her entire family, or why and when it happened. My sister's husband was a very good man. He had no enemies. They had built a new house in Daspara and were living there."

Soma Chakraborty, Ganapati's niece, said she had last spoken to her uncle on Thursday afternoon.

"After receiving the news on Saturday night, I came here and saw his body. The bodies of my aunt, sister and brother were also lying there. My uncle had no enemies. After retiring from school, he started working as a homeopathic practitioner," she said.

A local resident, Sudhangshu Chandra Das, said the family had been living in the area for the past four years. Ganapati had built the three-storey house, although construction work was still incomplete.

As the family was relatively new to the area, they had not developed close relationships with many people, although Ganapati was friendly and courteous, Sudhangshu said.

Rangpur Metropolitan Police Commissioner Mohammad Abdul Mabud said the incident was being investigated with the highest priority.

“We will know how they died once we receive the autopsy reports. Members of the Detective Branch are working in the field to uncover the facts and solve the case,” he said.