Navin Mahato (32), hailing from Dhanbad in Jharkhand, had been arrested under the Narcotics Act at Salanpur under Asansol sub-division and had been remanded in judicial custody here since March 30, 2015, Jail Superintendent Subhendu Krishna Ghosh said.
He said the undertrial had played cards with other prisoners early this morning after which he complained of chest pain.
He was rushed to Burdwan Medical College and Hospital when his condition deteriorated on the advice of the jail doctor, the official said.
Attending doctors at the hospital however, declared him brought dead. A swelling under the left eye was also noticed by the doctors.