The incident occurred in Nandinagar in Banjara Hills on Monday but came to light on Thursday after N. Sakkubai (55) succumbed to her injures in a hospital.
According to the police, N. Gopi returned home late on Monday night in an inebriated condition. After serving him the food, Sakkubai, who works as a domestic help, went asleep. He tried to wake her up for more rice. His sister Rani served him the rice. When he wanted rice for the third time, Rani asked him to go to kitchen and take it.
Angry over this, he hit his sister with a cricket bat. Hearing her screams, Sakkubai woke up and tried to intervene. Gopi also hit his mother on her head with the same bat, causing grievous injury.
The neighbours shifted both mother and daughter to a hospital, where Sakkubai died on Thursday. The condition of Rani is stated to be critical.
The police have arrested Gopi and registered a case. They are also probing the role of Gopi's wife Jyothi who was present in the house during the incident but immediately afterward left for her parents' house.