The accused, Ashwani Kumar was yesterday arrested by the crime branch, police said.
On the night of August 4, Kumar and his two associates, of which two were impersonating as policemen, had intercepted the car of the victim, who was coming from Gurgaon, in Janakpuri area and abducted him to Mianwali Nagar area and robbed him of his gold chain, 2 rings, wrist watch and one mobile phone.
The accused also stabbed him for resisting the robbery attempt, they said.
Officer also said that a manhunt has been launched against Kumar's accomplices Rakesh and Pramod Kumar, who would be arrested soon.