The police said that the husband of the woman was not found and may be behind the killings.
The decomposed bodies of a 30-year-old woman and her son were on Thursday found from a house in south east Delhi's Okhla area, police said.
The police said that the husband of the woman was not found, indicating that he might be behind their killings.
After neighbours informed the police about a foul smell emanating from the house, the police broke down its door and found the decaying bodies of the woman and her son.
The neighbours also told the police that the woman's husband, an auto rickshaw driver, had left two days ago after locking the house. They thought that the entire family had gone out somewhere, police said.
Many such cases of decomposed bodies have emerged in the recent past. Last week, a decomposed body, with the head severed, was found at Thiruvallam in Kerala.
Police had suspected that the body was that of 33-year-old Liga, a Lithuanian tourist, who had come for ayurvedic treatment for depression.
Two weeks ago, a young girl's decomposed body, her hand missing, was pulled out of a drain in Haryana's Rohtak. The girl's body was sent for post-mortem.
In February, the decomposed body of a woman customer care operator was found stuffed in a trolley bag at an apartment of a banker couple in Durgapur following which the man and his wife were arrested.
(With Inputs From PTI)