Paramilitary forces drawn from CRPF have been deployed to keep vigil at the office which has become virtually a hub of central security agency looking after internal security.
The tight security has been ensured keeping in view the importance of the arrested person who has been giving insight into 26/11 attack to the security agencies.
Around 50-60 armed security personnel are guarding the sensitive office located at Lodhi Road in south Delhi where the LeT operative is being held, a senior police official said.
The normally quiet office is abuzz with activities as Intelligence Bureau and NIA officials are engaged in questioning the 31-year-old Zabiuddin.
The media has been kept out the premises and are not allowed anywhere near the office.
"This is a different case. We have to take extra precaution and we are taking that," an official said.
Investigators claimed that Jundal told them that he was recruited into LeT in 2005 by a person hailing from Kashmir. He was indoctrinated after the post-Godhra riots, police sources said.
Jundal has married a Pakistani woman who is the daughter of an LeT operative. His wife is now in Karachi, they claimed.
