There were strangulation marks on the bodies of the two, identified as Phoolwati and her son Sunil (35), and there were no signs of robbery in the house as everything were in place, police said.
"We got a PCR call at around 4 PM about the incident after which a police team rushed to the spot. Both of them lived alone in the house and Sunil was a divorcee. Prima facie it appears to be case of personal enmity as the house was not ransacked for robbery," Deputy Commissioner of Police (South-West) Suman Goyal said.
A case has been registered at Inder Puri police station and further investigation is on, police said.