Police said neighbours got suspicious after the couple did not come out in the morning.
A carpenter, his wife, and their three children including a five-year-old boy were found dead in their house at Pudupalayam near Valavanur in Villupuram district on December 14.
Police identified the deceased as Mohan, 40, of Pudupalayam, his wife Vigneshwari, 37, and children Vimalashree, 10, Rajashree, 8 and Sivabalan.
Police said neighbours got suspicious after the couple did not come out in the morning. They broke open the doors and found the couple and their children dead and alerted the Valavanur police.
The bodies were retrieved and sent for post-mortem to the Government Villupuram Medical College and Hospital (GVMCH).
Preliminary investigation by the police revealed that the couple had killed their children and ended their lives allegedly over heavy debts.
A case has been registered and further investigations are on.
Assistance for overcoming suicidal thoughts is available on the State’s helpline 104 and Sneha’s suicide prevention helpline 044 – 24640050.