Security agencies have not as yet established a direct link between Irshad and last month's terror attack.
The Punjab Police have on an intelligence tip-off arrested an Indian national in Pathankot, who they allege is an agent of Pakistan's spy agency the ISI or Inter Services Intelligence.
The police said Irshad Ahmed was working undercover as a manual worker at the Indian Army's 29 Division Headquarter in the Mamoon Cantt in Pathankot, where terrorists struck an air force base last month.
Intelligence agencies have reportedly recovered several photos of sensitive installations from Irshad's smart phone.
The Pathankot Cantonment is one of the biggest and most sensitive military bases of the Indian Army. The Army division based there includes infantry battalions and cavalry.
Irshad's arrest is being seen as evidence that Pathankot, which borders Pakistan, is still on the terror radar despite security being strengthened after the Pathankot air base attack.
Security agencies have not as yet established a direct link between Irshad and last month's terror attack.
They are investigating how Irshad got his instructions from across the border. Sources said he had been tasked with collecting photographs of all sensitive installations and equipment inside the cantonment and was sending them to his Indian handler, Sajjad, in Jammu.
Sajjad was arrested in Jammu recently for possessing arms illegally. He is believed to have been a conduit between Irshad and Pakistani handlers and allegedly passed on the photographs sent by Irshad through email and chat messaging services.
Sajjad will now be questioned on the basis of what is revealed in Irshad's interrogation.
Six Pakistani terrorists attacked the Pathankot air base on January 2 and were killed in a gun battle that lasted nearly 4 days. Seven military personnel were martyred in the attack.