When the body of the deceased was sent for post-mortem, doctors reportedly found symptoms of strangulation.
An 81-year-old woman was killed at her home in South Delhi's upscale Greater Kailash area, allegedly by her help who tried to burn the body.
Neeraj Saki, 21, has been arrested for the murder of Rekha Duggal, his employer.
The crime was discovered on Monday night, after a neighbour reported a fire at Mrs Duggal's home.
Firemen found the woman's partially burnt body in the bedroom with the air-conditioner still on. Doctors said there were symptoms of strangling.
"The woman's body was found on the bed with a burnt
dupatta around her neck," said a police officer.
Forensic teams and investigators reportedly assessed that the body and the bed were set on fire deliberately.
Ms Duggal's daughter, who lived with her, was not at home at the time of the incident.
"The behaviour of Mrs Duggal's help, who lived in the house, was suspicious," said Deputy Commissioner of Police (South East) P Karunakaran.
On being questioned, Neeraj Saki reportedly confessed to killing his employer. He has been arrested.
Ms Duggal's husband K K Duggal was Editor of the United News of India and had died in 2005.