The body of N Suresh Babu alias 'Pottu Suresh' was found near his house at T V S Nagar near Sathyasai Nagar in the city, where Alagiri was staying, police said.
Suresh, an executive member of DMK, was allegedly involved in various cases, including murder and land grabbing.
He was also detained under the stringent Goondas Act in 2011, and was lodged in jail for about 100 days.
Police said there were two futile attempts to murder him earlier by some unidentified gangs.
A tense situation prevailed in the area after news about the murder spread and heavy police reinforcement has been deployed. Check posts have been alerted to nab the culprits, police said.