Investigations revealed the man had hacked to death his wife, father-in-law and child at Kakachchiveddai village, Vellaveli, Batticaloa. The deceased were identified as Perinpam Vijitha, 24, Prasanthan Sasnika, 18, and Kandaiyah Perinpam, 56.
The woman and the infant had been murdered at 1.00 a.m. and their bodies dumped into a well.
Perinpam living in a neigbouring house who heard his daughter screaming had rushed to her house when he was attacked by the man. He died on admission to the Batticaloa Teaching Hospital, investigations revealed.
The suspect was arrested later. The couple had been summoned to the Police to settle a family dispute on Friday. The man had complained to the Police that the child was not his. Vellaveli Police conducting investigations revealed this would have led to the dispute.