Three of a family were found dead at their house at Mattannur in the district while another member of the family was admitted to hospital in a serious condition, police said.
The body of Rajeevan (44) was found hanging from the ceiling while that of this wife Chitralekha (34) and son Amalraj (13) were found lying in the bedroom of their house.
They were suspected to have committed suicide, police said.
Rajeevan's daughter Amitha (12) was battling for life and has been admitted a hospital in Kannur and her condition is stated to be serious, police said.