The NIA, probing the terrorist attack on Pathankot air base, is likely to examine some personnel of the Indian Air Force to find out whether insiders played a role in the storming of the strategic installation.
However, so far there has been no indication that the six slain terrorists, who launched the attack on January 2, got help from someone inside the air base.
"The NIA is planning to examine some IAF personnel posted at the Pathankot air base. The NIA has already examined some people but found nothing suspicious," a senior official privy to the investigation said.
Around 5,000 people, including family members of IAF personnel, live in the nearly 2,000-acre air base located near the Indo-Pak border in Punjab.
"It is a large installation with several thousand people. So, it is taking time to completely rule out any probability of insiders role," the official said.
The NIA has almost come to the conclusion that the six terrorists, who were killed in the encounter that lasted three days, had inflitrated India through Bamial.
It is also largely believed that the terrorists had crossed the Indo-Pak border with arms and ammunition, the official said, scotching the speculation that weapons and ammunition were smuggled into India even before the terrorists came.
Seven security personnel were killed and several others were injured when six militants, suspected to owe allegiance to Pakistan-based Jaish-e-Mohammad, stormed the Pathankot air base.