The deceased were identified as Nisha Angel and her son Daniel. Police said Nisha, who got separated from her husband six months after their marriage seven years ago, was staying alone in her house in Athanur village near Guduvanchery.
On Thursday around 2 pm, the neighbours noticed smoke coming from the house and when tried to open the door found it locked from inside. Since there was no response from Nisha and Daniel even after repeated knocking, the neighbours broke open the door and found the mother and son charred to death in the living room.
Police arrived at the spot and retrieved the body and sent it for post-mortem to the Chromepet Government Hospital. Police sources said the LPG cylinder in the house did not burst and the reason for the fire is to be ascertained.
The police have registered a case and are investigating whether Nisha was depressed and had taken the extreme step since she was living alone for nearly six years.
Police are also probing whether there is someone else behind the incident.