Nasiruddin had died in police custody on January 18.
Congress workers have alleged that Nasiruddin died following torture by the police.
"Why was the post mortem done in a hurry? It was a farce to cover up the case. We want a fresh post mortem and a CBI inquiry into the custodial death of Nasiruddin," said Bhattacharya accompanied by the wife and family members of the deceased.
"The Governor has expressed his sorrow over the incident. He has assured that he will look into the matter," Bhattacharya said.
He also alleged that the alleged custodial death of Nassiruddin was a result of factional feud within TMC.
On the day of the incident, Hooghly Superintendent of Police Tanmoy Roychowdhury had said Nasiruddin was taken to the police station by a night patrol after finding him in an inebriated state.
He said Nasiruddin's wife Manuja Begum filed an FIR at the police station that her husband, a resident of Jairambati village, was allegedly beaten to death by the police.