National Investigation Agency (NIA) has served formal notices to at least two mobile telephony service providers, asking them to give details of numbers from which three emails were sent to the media and Delhi Police, claiming responsibility for the Delhi high court blast.
The NIA informed them that if they failed to do so, they would be liable for prosecution.
The lead on the first email, sent from a cyber cafe in Kishtwar in Jammu and Kashmir, has also run dry as the student picked up in this connection has denied sending any such mail in the name of Harkat-ul-Jehad-al-Islami (HuJI).
NIA sources said formal notices were issued to service providers as these companies have not been able to dig out the numbers and cell phone locations from which three emails — two in the name of firstname.lastname@example.org and one with email@example.com — were sent to media organisations after the blast.
The last email signed by one Ali Saed El-Hoorie had threatened to target Ahmedabad and the first mail had indicated a strike on a mall.
While the first mail from Chotoo had been initially traced to Kolkata, it turned out to be a false lead.
To further complicate matters, the Kishtwar schoolboy Sunny Sharma, who was detained by the J&K Police for allegedly sending the HuJI mail, has flatly denied sending any such message. Sharma has apparently accepted that he was in the cyber cafe between 1.00-1.30 pm on September 7 but said he had nothing to do with the HuJI mail.
With the case still blind, the NIA is now waiting for the Gujarat forensic science lab report for details of the IED used.
Though the NSG bomb team had concluded that a nitrate-based explosive was used for the blast, there is no confirmation on either a switch or PETN being used by the terrorist last Wednesday.