Although no arrests have been made yet, police questioned 12 persons in connection with the shooting of the 62-year-old business tycoon-turned-politician.
Police sources say the assailants, who were seen leaving the farmhouse in a car belong to Khera village in Pooth Khurd area of northwest Delhi which is near Haryana border.
Moreover, Delhi police with the help of Haryana cops have recovered a Skoda car, in which the killers travelled on Tuesday night from Jind area in Haryana.
Delhi police also questioned the family members of Bhardwaj to find out whether "property dispute" led to BSP leader's murder.
A senior police official told media persons that police spoke to Bhardwaj's wife and sons. Apparently, the wife was staying separately from her husband. Police sources say probe team questioned family members to ascertain whether there was a property dispute and if he had any "enemies".
Bharadwaj, the richest candidate in the 2009 Lok Sabha polls with declared assets of over Rs 600 crore, was fired upon from point blank range by three men who fled after the incident.
He was gunned down by the trio who entered his farmhouse in Rajokri at 8:55 AM on the pretext of booking the place for a marriage, Delhi Police Commissioner Neeraj Kumar had told reporters here.