Communist Party (Marxist) leader Mohammad Salim was leading a protest march through the city. The gang raped victim's body was being taken to the centre of the Indian Trade Unions office. The victim's family is demanding justice.
Salim has accused the police of conspiracy.
Earlier it was reported that protesting civil society members would approach West Bengal Governor M.K.Narayanan to seek his intervention in the matter.
Media reports said the meeting with Governor Narayanan is expected to take place at around 12.30 p.m. on Wednesday.
The girl, who was allegedly gang-raped two months ago, died in hospital on Tuesday, more than a week after she set herself on fire.
Her father, a taxi driver, is reportedly a member of the Communist Party-Marxist trade union, which wanted the teen's body to be kept in a mortuary overnight and then taken for cremation in a protest procession today.
There have been protests since yesterday over the girl's death.
But the girl's family alleges that when they were taking her body from their home to the mortuary on Tuesday, police intercepted the hearse and forced it to drive to the cremation ground.
They alleged that the policemen tried to cremate the body, but could not do so, as they did not have the death certificate.
At their home, the family alleged, some policemen and local goons attempted to force the father to hand over the death certificate, but he did not.
They said the body was brought back by cops to the girl's home nearly five hours later, at about 2.30 a.m.
At 6 a.m. this morning, the father of the girl left with the hearse for the crematorium. The police have accompanied him.
Last rites are yet to be performed as the father is reportedly adamant that he will decide when to cremate his daughter, not the police.
The distraught parents have demanded the death sentence for the rapists and for those who tormented her so much that she set herself ablaze.
"I will fight the case. I will not let them go. I will not take my last breath till they are hanged. That's my promise," the father said yesterday.
The girl, allegedly gang-raped twice in October by the same set of people, had set herself on fire on December 23, after being harassed by friends of the men arrested in the case.
The girl's father had moved his family from Madhyamgram, about 40 km from Kolkata, to the airport area closer to the city, but the harassment and threats to withdraw charges continued.