The special investigation team probing the collectorate bombing case is hunting for a tech-savvy terror operative, who seems to have made the bomb for the 2009 blast on the fifth storey of the building.
According to police, the bomb used for the blast had a timer attached to it, which suggested only a technologically advanced person could make it.
A forensic examination of the bomb revealed that a local newspaper, dated June 5, 2009, was used for the bomb-making. It meant the bomb was made just five days before the incident.
LeT suspects like Thadiyantavide Nazeer and KP Sabir were not in the country during the time the bomb was manufactured.
However, Abdul Halim, a childhood friend of Nazeer, a suspected LeT operative and bomb expert, was in the state at the time. The SIT quizzed him on Mondays in connection with a quotation case, police added.