A state CID officer said teams from the homicide department had been sent to the spot near Mankundu railway station in Hooghly district to investigate the unnatural death of Manna.

"They will verify the place where the body was found and also visit the Walsh hospital in Serampore where the autopsy was done," he said.

Yesterday, Officer in-charge of Sheoraphuli Government Railway Police(GRP) S Bhattacharya had said "prima facie it is a case of suicide"

Meanwhile, the family members of Manna claimed that there was enough evidence to prove that Manna had been murdered. "Arindam had two mobile phones - one had Vodafone (9836700511) and the other had Airtel (9903037757) connection. The police recovered the cell phones, but the SIM cards are missing," Manna's brother Debaprasad Moitra claimed.

"The SIM cards have been deliberately taken out to destroy the evidence. Arindam's hands and legs have been broken and his eyes were jutting out. This cannot happen in a suicide. It is a murder and we want the criminals to be punished," Moitra said.

A second post-mortem on Manna's body will be carried out today after his family members lodged a complaint at the police station in Dasnagar that the previous autopsy at Walsh Hospital in Serampore yesterday was carried out in a hurry.

The autopsy would be carried out at the Calcutta Medial College and Hospital following an order by District Magistrate of Howrah Khalil Ahmed.

ADG (Railways) Dilip Mitra said the police had lodged a murder case at Seoraphuli GRP and that he would personally look into the matter.

At Dasnagar in Howrah district, where Manna's family stays, the district Youth Congress workers today observed a 12-hour bandh to protest against the unnatural death.

They also blocked the rail tracks on the Howrah-Kharagpur section of South Eastern Railway this morning disrupting train services for 20 minutes.