An inmate of Dhaka Central Jail in Keraniganj died at Dhaka Medical College Hospital (DMCH) on Tuesday morning.
The deceased was identified as Anowar Hossain alias Khabir Uddin, 55, son of Asiul Haq in Al Amin village of Hatia upazila of Noakhali district.
He was taken to the hospital after falling ill and was declared dead around 10:30am, said Dhaka Medical College Hospital (DMCH) police outpost in-charge Md Bacchu Mia.
"The body was kept at the hospital morgue for an autopsy," he added.
"The deceased was incarcerated in a drug case."