The woman, Kallavva Dadu Kamble, ended her life on the night of November 13 in Bamani village, an official said.
"The deceased woman was living alone next to her 57-year-old son Vitthal's residence in the village," he said.
On the evening of November 13, her grand-daughter allegedly gave her food and Kallavva then went to sleep at her home. The elderly woman then locked the door of her home from inside and arranged her own pyre with wooden sticks and cow dung, poured kerosene and ignited it with a match stick, the official said.
"Next morning, Kallavva's grand-daughter came to her house with a glass of milk for her, but on finding that she is not opening the door, she informed her father about it," he said.
Vitthal, who is a conductor with the state transport department, rushed to his mother's place and broke open the door. As he entered the house, he spotted the ashes and some half-burnt body parts in the middle of the room, he said.
Superintendent of Police, Kolhapur, Sanjay Mohite, said, "The woman was fed up with her life, that is the reason she took the extreme step and ended her life."
Police have registered a case of accidental death in this connection and further investigation is on, he said.