Police said the accused also tried to rape the women before setting her on fire.
The accused, identified as Neeraj Saki, had made a foolproof plan to show as if the woman had died in an accident but forensic evidence and police investigation led to his involvement in the incident, following which he was arrested.
According to police, Rekha Duggal, wife of K K Duggal, used to live on the ground floor of her house in GK-II.
"The teams of CFSL, CBI and Delhi Fire service were called to examine the crime scene. They opined that the bed and the body were deliberately set on fire.
"At this the conduct of the servant, a resident of Madhubani in Bihar, who used to live in the same house was found to be suspicious," Deputy Commissioner of Police (South East) P Karunakaran.
According to another official, the first floor of the house belonged to Duggal's daughter Sadhna, which the deceased had gifted to her.
"During interrogation, Neeraj revealed that finding Duggal alone in the house, he tried to sexually assault her. But when the old woman fainted during the scuffle, he sprinkled petrol on her when she was lying unconscious and set her on fire," the official said.
Duggal's husband K K Duggal was Editor of the United News of India (UNI) and had died in 2005.
