The Palwal police have visited the hotel in Agra where the woman, who was found murdered on National Highway number two last week, stayed with her husband.
They are also scanning the CCTV footage of cameras on the Yamuna Expressway, on which the couple initially ventured out to travel from Delhi to Agra.
The woman, Satvinder of Mayur Vihar phase 3 in Delhi, was found murdered in the bushes close to National Highway a few days ago.
The victim and her husband Mukesh Lakhanpal were in their Maruti Swift car and were on way to their Mayur Vihar Phase residence from Agra when the incident took place.
The cops questioned Mukesh on Monday at the Palwal Sadar police station and he was let off the same day. Later, some relatives of Mukesh in Delhi were also questioned.
"Mukesh told us that he was married to the deceased for the last seven years and it was their second marriage," the police said, adding that both the victim and her husband had two children from their first marriage.
The police claimed that Satvinder was living in an encroached house along with her partner in Delhi. "During investigation, we came to know that Satvinder Lakhanpal was living with her partner Mukesh in her uncle's house in Mayur Vihar Phase-3," officers said, adding that they both had encroached the house.
Police said when the couple stopped their car near a toll plaza close to Aurangabad in Palwal, four car-borne armed youth attacked, robbed them before killing the woman.
Police came to know about the incident when some villagers saw an abandoned car and a man (Mukesh) lying under some bushes with hands and legs tied.