A leader of Left party CPI-M's student's wing has died of injuries that he sustained while in police custody in Kolkata today. Sudipta Gupta, 24, and several other leaders and activists of the Students' Federation of India or SFI, were rounded up by the police while they were protesting this afternoon against the Mamata Banerjee government's decision to put off college union elections in the state. They were put in buses and taken to Presidency Jail.