Tanvir Mahmud, the managing director of the  Hallmark Group, died while undergoing treatment at  Dhaka Medical College Hospital on Saturday night.

He passed away around 10:30pm, said  Jannat-ul Farhad, AIG (Development), adding that Tanvir had long been suffering from various health complications while in prison. He was 55.

Earlier in the afternoon, his condition deteriorated inside the  Dhaka Central Jail in Keraniganj, prompting authorities to shift him to DMCH for treatment. His health further worsened after admission, and doctors declared him dead at night.

According to a statement from the  Directorate of Prisons, Tanvir had been critically ill for an extended period, suffering from high blood pressure, diabetes and multiple other complications.