The 23-year-old student died after police allegedly beat him up severely, when he and his fellow activists were protesting against Mamata Banerjee's government decision to put off college union elections on Tuesday, April 2.
The post-mortem report of the deceased activist is likely to come up on Wednesday.
Moreover, death of Gupta has once again raised the issue of law and order situation under Trinamool Congress (TMC) government in West Bengal.
Eyewitnesses said Gupta died because of police brutality, as they pushed Sudipto out of the running bus. SFI General Secretary Satarup Ghosh, who is an eyewitness, said, "He was hit on his head so hard that one of his eyes came out."
The grieving father of Sudipto, Pranab Gupta said, "He died, what was his fault?"
"The people responsible should get adequate punishment," the father added.
Javed Shamim, Joint Commissioner of Police, Law and Order, said, "There was a scuffle inside the bus as the students shouted slogans. One of the students hit a lamp post and was critically injured."
An FIR has been lodged over the incident. The Left Front wants a judicial probe into the incident. Leaders of Left Front said if justice was not delivered, protests would break put across West Bengal.