Their servant Sikander, hailing from Assam, was missing and initial police investigation was focussed on his role in the double murder.
A retired income tax officer and his ailing wife were found murdered at their residence in a posh Central Delhi locality on Monday.
The bodies of Dev Raj Grover (74) and Vimla Grover (70), with their necks slashed, were found on Monday morning at their house in East Park, which was ransacked by the assailants, police said.
Their servant Sikander, hailing from Assam, was missing and initial police investigation was focussed on his role in the double murder.
The Grovers had hired him from a Green Park placement agency four days back.
Police is verifying his antecedents and a hunt is underway to find him.
The couple were staying with their grand son Ashish Grover, who was not in the house on Sunday night as he had gone to his parents place.
They have two daughters and a son, who runs an export house in Mansorovar Park.