Kolkata, Apr 5 (IANS): The preliminary post-mortem findings of student leader Sudipto Gupta indicates his body and head hit a "blunt, stationary" object before falling on a rough surface and that there were no injury marks from "laathi (baton) or rod or glass", police said Thursday.

"The post-mortem report which is very indicative, very important to us, that the death was due to head injuries that was ante mortem (before death) in nature. The injuries are consistent with the body and head hitting a blunt stationery object and subsequent fall on a rough surface," Kolkata police Joint Commissioner (Headquarters) Jawed Shamim told media persons here.

However, Shamim said he was sharing only a part of the post mortem report "which is very indicative".

"No marks of injuries from laathi or rod or glasses as such have been found on the body," Shamim said referring to the report.

But the senior police officer said investigation was on and police were looking at all aspects.

"We are not here to rule out anything, nor are we ruling out anything," he said.

He assured the scribes that the investigation would be carried out in a "very transparent manner" and hoped to "arrive at a conclusion very quickly".

He made an appeal that the media refrain from coming to a conclusion on the incident till the probe was complete.

"We will be obliged to you if you report in a balanced way. We have been seeing the reporting in the case of Sudipta Gupta in electronic as well as print media.. they are coming to conclusion when investigation is still on," he said.

Shamim said two cases have been lodged on the incident.

"We had lodged a complaint initially of rash and negligent driving by the driver which led to the unfortunate demise of Sudipta Gupta."

Soon after the incident occurred Tuesday, Shamim had said Gupta died after his head hit a lamp post.

"But subsequently a complaint had been lodged by an SFI supporter that the death happened because of unknown policemen beating up Sudipto Gupta, on that basis also an FIR has been lodged against unknown policemen and the investigation is progressing," said Shamim.

Gupta, 24, an activist of Communist Party of India-Marxist's (CPI-M) affiliated Student Federation of India (SFI) activist, died in police custody Tuesday here after he took part in an agitation.

Left activists said Gupta, a post-graduate student of Rabindra Bharati University, was "mercilessly beaten" while he and other students who had staged a protest seeking elections in colleges, were being taken in a bus to the Presidency Correctional Home.

In the process, Gupta reportedly fell from the bus and collapsed after crashing against a lamp post, said an SFI member.