An inmate of Dhaka Central Jail in Keraniganj died at Dhaka Medical College Hospital (DMCH) on Sunday afternoon.
The deceased was identified as Rajit Kumar Saha, 42, son of Rabindranath Saha of Manikganj Sadar upazila.
Inspector Bachhu Mia, in-charge of DMCH police camp, said Rajit Kumar was brought to the DMCH on May 23 from Keraniganj Central jail as he fell ill.
He said the on-duty doctor declared him dead around 5:30 pm on Sunday while he was undergoing treatment in the medicine department of the hospital.
The body was kept at the hospital morgue, Inspector Bachhu Mia said, adding that Rajit Kumar was convicted in a murder case.