Seema Bhardwaj was arrested on Thursday after she confessed to her crime of killing her 40-year-old husband Om Bhardwaj inside their residence in Najafgarh area of west Delhi on the intervening night of August 15-16.
Police said the woman, a mother of two children, narrated the entire incident to her sister-in-law on Thursday.
"She wanted to get rid of the continuous torture of her husband who had been beating her regularly for over last five years whenever he used to consumed liquor," Deputy Commissioner of Police R.A. Sanjeev told IANS, citing the woman's confession before interrogators.
"She was also discontented over continuous complaints received about her husband from their neighbours," the official said.
Police said Seema Bhardwaj had decided to eliminate him a few days before the incident. For this, she had sanitised the septic tank of her house.
"She strangulated her husband to death on the intervening night of August 15 and 16 and concealed his body in a bed and later dumped it in the septic tank," the official said.
Police recovered the decomposed body from septic tank on Thursday and sent it for a medical examination.