V Ramesh, BJP Tamil Nadu unit general secretary, was killed by a gang near his office in Salem district late on Friday night.
Police said a gang of persons waylaid him and hacked him to death near his office at around 10 pm.
A chartered accountants, Ramesh, 54, was recently appointed the spokesperson of the party's Tamil Nadu unit. He was returning to office at night when a group of persons grabbed and attacked him with sharp weapons.
He was badly injured in the neck and head and died on the spot, a BJP leader from Salem told television channels.
Senior police officials rushed to the spot for investigations. His body was taken to Salem Government Hospital for post mortem.