Ajijur Rahman, picked up last night and taken to Kallain police station, had complained of uneasiness and was taken to the local hospital. He was referred to Silchar Medical College Hospital but died on way, Cachar Superintendent of Police Diganta Bora said.
Bora said IPS probationer Y T Gyatso, who led the team which picked up Rahman, has been relieved of duty.
Rahman's family members had filed an FIR at Kallain police station.
The clash took place at Kallain and adjacent areas during the 12-hour Barak Valley bandh by Hindu Jagran Manch that left 22 injured and led the administration to clamp an indefinite curfew, which was lifted yesterday.
The bandh was called to protest harassment in the name of search for those who had assaulted Congress MLA Rumi Nath and her second husband on June 29 in Karimganj.
All India United Democratic Front MLA of Katigora assembly constituency, Ataur Rahman Majarbhuyan has demanded action against the police for picking up Rahman who was in frail health.
He also demanded Rs 20 lakh as compensation for the victim.
