The incident took place at Harishchak village in Khanakul when angry Trinamool workers allegedly hit Sudam Pramanik with a sharp weapon in his head.
Sudam was a member of the BJP-run Zilla Parishad in Hooghly district.
He was hacked to death by the Trinamool-backed miscreants, Bharatiya Janata Party supporters claimed. The area Trinamool Congress leadership denied the allegation, claiming the incident occurred due to BJP infighting.
According to police sources, a case has been filed at the area police station.
"We have begun investigation to find out who actually attacked Sudam Pramanik with a sharp weapon. No one has been arrested so far," a police official said.
Sources said that the flag-hoisting ceremonies was held by both the parties at the same place in the village, which led to a heated altercation between the rival groups.
District Trinamool Congress leader Prabir Ghosal said: "I heard about the incident. It was unfortunate. But the Trinamool Congress is not involved in the clash. It took place because of the internal feud of the district BJP workers."
The TMC leader also demanded an impartial probe into the incident. "I don't want to say anything as it would be too early to comment. We urge the police to conduct a thorough investigation into the incident," he added.