The jail authorities said Atiquzzaman Pintu fell sick at around noon and they sent him to Dhaka Medical College Hospital (DMCH) where doctors declared him dead.

His elder brother Mohammad Shafiquzzaman alleged the 35-year-old contractor died as the jail authorities did not provide proper treatment for his 'poor heart condition'.

Keraniganj police held Pintu in June last year after a gunfight between police and gangsters of Yunus group and later sent him to Dhaka Central Jail. He suffered a cardiac attack in jail 20 days after he was arrested, he added.

Family members met the jail authorities and repeatedly pleaded for arranging appropriate medication for his well-being, but their requests went unheeded, Shafiq alleged.

Jail authorities also ignored their lawyer who sought better medical facility for his client, he added.

His body was kept at the DMCH morgue for autopsy.