However, the police have not been able to link him to any terror plot as per the investigations that have taken place till now.
"The police have managed to decode the emails and documents of accused Sameer Sardana and has found that he was collecting information about past bomb blasts in the country," a senior ATS official told PTI.
The ATS and Intelligence Bureau, which have been interrogating the 44-year-old chartered accountant, cracked the password of his laptop which he had refused to divulge during questioning, the official said on condition of anonymity.
"(However), we have not been able to link him to any terror plot as per the investigations that have taken place till now. But inquiries are on," the official said.
Sardana is based in Mumbai and has worked for MNC firms like Accenture with postings in Hong Kong, Malaysia and Saudi Arabia, the official said.
Police investigations have also revealed that he is a Hindu by birth but has been practicing Islam.
He is the son of a former armyman from Dehradun, and was apprehended by the ATS on Monday.
Police had found five laptops in his possession and had sent them to cyber crime cell for examination.
Sardana was booked under section 41 of the CrPC which deals with preventive arrest.
According to police, Sardana was living in a railway dormitory, 35 kms from Panaji, since January 22 and has been extending his stay.
He was questioned after he was constantly seen sitting on railway platform and busy on laptop for hours together, police had said.
The Goa police are on alert after a letter purportedly written by ISIS, threatening to kill Prime Minister Narendra Modi and Defence Minister Manohar Parrikar, was received on January 13 by the state secretariat, which was handed over to the ATS.
Police had detained a Syrian, a Nigerian and a Yemeni last week for overstaying and they were probed from the terror angle.
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