The man, whose wife and children were found dead a few days ago at Pothukal near Nilambur, ended his life on Wednesday.
Bineesh Sreedharan, 36, was found hanging from a tree.
His wife, Rahna, 35; sons Adityan, 12; Anandu, 11; and Arjun, 8; were found hanging in their house on Sunday.
Call for probe
Rahna’s family had demanded an investigation into the role of Bineesh in their death.
Family issues
The police said some family issues led to the mass suicide.
Assistance for overcoming suicidal thoughts is available from the State’s health helpline 104, Sneha’s suicide prevention helpline of Maithri (0484-2540530), Thanal Suicide Prevention Centre (0495-2760000) and Direction Interventions System for Health Awareness (DISHA – 1056).