Kolkata student leader's death: CCTV shows protesters allegedly beating up cop

CCTV footage from near Kolkata's Presidency Jail has been released, throwing no light on how student leader Sudipto Gupta died in police custody on Tuesday but showing his party activists allegedly beating up a policeman.

Video from police cameras also shows a student with head injury, but Students Federation of India (SFI) activists point to his red T-shirt to say he is not Sudipto, who was wearing blue that day.

Sudipto was among the SFI students arrested on Tuesday while protesting against the Mamata Banerjee government's decision to postpone college union elections.

The Chief Minister has backed the police, which says his death was an accident caused when he hit a lamp post while hanging out of a bus taking the protesters to jail. But SFI leaders allege the police thrashed Sudipto with batons and he suffered head injuries.

One CCTV camera, located somewhere on a road leading to the jail, shows SFI activists running after a man, apparently Home Guard Biswajit Mondal. Five minutes later, at 2.47 pm, they are seen apparently roughing him up.