The body of Nandagopal Thakur (53), a BJP member of Kanaipur gram panchayat, was found near the tracks between Sheoraphuli and Diarah railway stations, according to Government Railway Police (GRP) officials.
The GRP said no external injury was found on the body, which has been sent for postmortem.
An enquiry into the incident has been initiated.
District BJP vice-president Swapan Paul said Thakur had been campaigning against the Trinamool Congress (TMC) in Hindmotor municipal area for the April 25 polls.
Denying the allegation, TMC district president Tapan Dasgupta said BJP has been levelling baseless charges as they know they would not win the election.