The family of Mahbubur Rahman Sujan plans to file three cases, including one for murder, accusing Sub-inspector Jahidur Rahman Khan of Mirpur Police Station of torturing Sujan to death on Sunday.
Victim's brother-in-law Omar Faruk yesterday said they would also accuse Officer-in-Charge Mohammad Salauddin, SI Asad and a few others of the police station.
They were preparing to file the other two cases for torturing Sujan's widow Momtaz Sultana Lucy and their five-year-old son Rabbi, said Faruk.
He added if the police denied taking the cases, they would go to the court.
Sujan, a garment waste trader in Mirpur, was picked up from his Shankar residence in the wee hours of Sunday by a team of Mirpur police led by SI Jahidur.
He was allegedly beaten up at his house, inside the police van and at the police station overnight and subsequently died in police custody in the morning.
Since the incident, SI Jahidur could not be contacted either physically or over the phone for comments.
Asked if any action was taken against him, Home Secretary Mozammel Haque Khan replied in the negative, saying that the ministry does not directly take measures against non-cadre officers.
"The police will take necessary action in this regard and will inform us," he told The Daily Star, adding that the ministry was monitoring developments.
Contacted, Inspector General of Police Hassan Mahmood Khandker said, "We have initiated an investigation into the matter."
The IGP denied making further comments, saying it would not be appropriate to make any remark at the investigation stage.
Morgue sources said injuries to Sujan's head, hands and other parts of his body caused his death, giving substantial grounds to his family's claim that he was tortured to death.
His son Rabbi, who was taken to the police station along with his parents, said he had seen how police had raided their house and brutally tortured his parents leading to his father's death.
Rabbi added he had gone down to his knees following his mother as they both begged SI Jahidur to release his father.
The men in uniform reportedly went to Sujan's house to extort money from him.
Sujan's widow Lucy claimed the Mirpur OC had forced her to sign on a blank sheet of paper on Sunday morning.
OC Salahuddin could not be contacted for comments.