Saikat Bhawal was declared "brought dead" by doctors at the hospital.
A BJP worker was beaten to death and six others were injured when a group of people attacked them during a door-to-door campaign of the party in West Bengal's North 24 Parganas district on Saturday, the police said.
Saikat Bhawal was one of those who were assaulted. When he was taken to the hospital, doctors declared him "brought dead", the police said adding that the matter is being investigated.
Six others, who were also injured in the attack, were admitted to the hospital.
Barrackpore BJP MP Arjun Singh alleged that goons sheltered by the Trinamool Congress killed Saikat Bhawal but the ruling party denied the charge.
Arjun Singh said that the party will launch a protest in the district against the incident on Sunday.
The BJP said that the party activists were attacked when they were engaged in the "Griha Sampark Abhiyan".
It's a public outreach programme which is part of BJP's "Aar Noi Annay" (No More Injustice) campaign launched in the run up to the state Assembly election due in April-May next year.
TMC MLA of Naihati, Partha Bhowmik, claimed that Saikat Bhawal's death is the result of an old dispute between two groups of the locality and the BJP is unnecessarily politicising the incident.
He said that the TMC will not allow BJP to disturb the peaceful situation in the district.
Joint Commissioner of Barrackpore Police Commissionerate Ajay Thakur said that two persons have been detained in connection with the incident and are being interrogated.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)