A team of NIA officials flew in a special aircraft to Jammu yesterday evening and seized two mobile phones from the house of Wasim Ahmed, a student of Unani medicine in Bangaldesh, who has been arrested by the by the agency in connection with the blast, official sources said.
The team then left for Kishtwar in a helicopter and recovered another phone and some documents, they said.
The sources said agency is expecting a breakthrough in the case soon.
So far, Ahmed and suspected Hizbul Mujahideen operative Junaid Akram have emerged as prime conspirators of the High Court blast which killed 15 persons on September 7.
Ahmed was arrested from Indo-Bangla border in connection with the blast.
Of the three people arrested earlier by the NIA in, one has been let off.
From the leads emerging in the case so far, the investigators suspect that it could be the handiwork of Pakistan-based terror outfit Hizbul Mujahideen and not Harkat-ul-Jehad-Islami (HuJI) as believed earlier.
Information about Ahmed was given by Azhar Ali, an overground worker of Hizb, who is in Kotbalwal Jail in Jammu since 2009,the sources said.
An NIA team had questioned Ali, arrested for alleged involvement in recruiting people from Kishtwar area besides securing SIM cards for the outfit, to know about some of the youths, including Akram, whom he had allegedly sent for training to Pakistan-occupied-Kashmir, the sources said.
Though NIA claimed that Akram was in Pakistan, sources in the security agencies believed that he was in Jammu and Kashmir.
NIA has arrested Abid Abbas, a high school boy, on charges of having sent an email after Delhi High Court blast. The probe agency had detained Abbas' brother from Shillong who expressed complete ignorance about the matter.
The NIA team has so far questioned two students including a girl, both hailing from Kishtwar, about the conduct of Wasim Akram.
Both students have been let off after the NIA team, which was provided assistance by the Bangladesh authorities, found nothing to back their investigation, the sources said.
In a related development, Wasim's arrest has been decried by his family members who said he was being made a scapegoat and had no role to play in the blast.
Wasim was allegedly linked to Junaid, who, NIA claimed, had received training in Pakistan-occupied-Kashmir (PoK), a charge rebutted by his father Reyaz Malik.
Reacting to the allegation, Malik said it was nothing but a bunch of lies being spread about his sons.
Recalling the incident, he said his son had gone missing last year in August after appearing in his matriculation exams and said that his date of birth was May five, 1995.
He also narrated that it was surprising that while they had lodged an FIR about him going missing in Kishtwar police station, his son was being labelled as terrorist.
He alleged that it was an act of vengeance orchestrated by Hizb conduit Azhar Ali, whose family had been their tenant in Kishtwar.