Sharbani Pal, 60, was living in the house with her brother Amarnath Pal, 64. The police said they are awaiting the post-mortem report to determine how Mr Pal died.
Last month, the body of an elderly woman was recovered from a freezer, the kind used to store ice cream in commercial outlets, from a house in Kolkata. The woman, Bina Majumdar, died in April 2015 when was she 84 years old.
Her son, a leather technology graduate, allegedly mummified the body with chemicals before keeping it in the fridge.
Acting on a tip-off, the police raided Mr Majumdar's house on James Long Sarani in south-west Kolkata's Behala area and found the body. A second freezer was also found in the house.
Bina Majumdar was an employee in the Food Corporation of India or FCI and drew a monthly pension reportedly of Rs 50,000. Her husband also worked at FCI till retirement.
In a similar case in 2015, Partha De, 44, was found living with the bodies of his sister, father and pet dogs for almost a year at the family house on Robinson Street in Kolkata.