The initial probe has revealed that Shakil alias Ramesh, a native of Pakistan, was in the know of the security details of the chief minister's office and a major incident had been averted after his arrest, highly placed police sources told UNI.

The arrest is also being looked upon by other agencies of the country as an 'important' catch, particularly in view of the fact that the Uttar Pradesh police was the first to trace the email sent five minutes before the Ahmedabad blasts to Navi Mumbai.

Shakil, who was working as an employee of a glass showroom, used to frequently visit the secretariat annexe posing as a glass fitter. It was easy to do as construction and renovation work has been on in the secretariat ever since the Mayawati [Images] government came to power last year.

As regards to his reported 'meeting' with a senior official in the secretariat, officials have denied it but admit that Shakil had a temporary entry pass valid for three hours in March 2008. The multi-agency investigation has so far come to the conclusion that Shakil was working for a terrorist module and was in constant touch with a terror outfit.

''We are probing if he was part of a terror module in UP, something vital is likely to come out very soon,'' the officials claimed.

Shakil, they said, was residing in Lucknow for about three years and the task assigned to him was still to be investigated. ''His arrest will throw light on terrorist activities in UP which has seen some of the worst attacks like the Ayodhya attack, bomb blasts on the Shramjeevi Express and the attack on Varanasi's Sankatmochan temple."

The security mechanism was also trying to unearth Shakil's connections in Varanasi. How Shakil obtained a fake driving licence and ration card is also being probed.