The deceased has been identified as Umesh(45), a resident of Chapuradoddi village near Maddur town.
According to police, a manhunt has been launched for the accused who had fled the crime scene.
The now-deceased Umesh was married to Savitha 20 years ago. There was marital discord between the two.
Savitha had moved in with her son Shashank in Bengaluru after he got a job in the city and settled down there.
She had come to the village to participate in a function on Thursday and when she went to her house, Umesh refused her entry leading to a heated argument.
Umesh had made certain allegations which enraged her and she called her son Shashank to the village.
After he arrived, both questioned the man over the allegations and attacked him with wooden pieces.
Umesh died of severe head injury.
On realising that he had died, the accused mother and son fled the spot.
The victim’s parents lodged a complaint in this regard with the Besagarahalli police station.
An investigation in the matter is on.