Four persons, suspected to be involved in the murder and abandoning of the body in a sack at Marayur, were arrested on Monday.
The body was found by people living near the area on Monday morning.
The victim was Mariyappan, 70, father of former grama panchayat president and present ward member Usha Thampidurai.
Mariyappan, an astrologer, was in Tamil Nadu and returned to Marayur on Sunday night.
Instead of going to his house, he stayed with his friends in a rented house.
Quarrel
It is suspected that Mariyappan was killed following a quarrel after they consumed alcohol.