The police have launched a manhunt for two unidentified men for the fatal attack on senior neurosurgeon S. D. Subbiah on September 14.
The police are also searching for a family of five including an elderly woman, which is believed to have ordered the attack.
The 59-year-old doctor, who was hacked with sickles at R.A. Puram, succumbed to his injuries on Monday morning.
The attack by the two backpack-carrying men was caught on a CCTV camera installed in a building opposite the scene of crime.
On September 14, the neurosurgeon was walking out of a private hospital in R.A. Puram where he had joined as a consultant following his retirement from Rajiv Gandhi Government Hospital as a professor of neurosurgery in July 2013.
The CCTV footage shows the doctor lying unattended for a long time after the assailants inflicted multiple injuries on him and walked away.
While some passersby were mute spectators, most others fled the scene. Gradually, a crowd gathered and the police were alerted.
According to police sources, a team from the Abhiramapuram police station arrived at the spot and Subbiah was taken to the private hospital where he worked.
Four special teams are probing the murder and trying to establish the identity of the two killers and their accomplice who was waiting on a motorcycle nearby.
While undergoing treatment, Subbiah told investigators that a longstanding dispute with some of his relatives over a Rs. 15-crore property in Anjugramam, Nagercoil, had led to the attack.
Investigators have launched a hunt for a Nagercoil-based family —Annappazham, her son Ponnuswamy, his wife Mary Puspam, and the couple’s sons Fasil and Boris — which, they believe, were behind the attack, sources said.