The Jaish-e-Mohammed leader who gave directions over phone to the terrorists during the attack on the Pathankot airbase has reportedly managed to flee to Afghanistan from Pakistan, an official said.

"The alleged JeM handler who communicated by telephone more than two-dozen times with the terrorists in Pathankot before they carried out the attack on the airbase on January 2 has managed to cross into Afghan border," a member of the Joint Investigation Team probing the attack told PTI on Thursday.

He said the JeM handler, who is in late 20s, was in the tribal area of Pakistan when he communicated about 18 times with the terrorists.

"The law enforcement agencies tried to trace him (in the tribal belt) but there are reports that he managed to escape to Afghanistan," he said, without disclosing the JeM leader's identity.

Interestingly, during interrogation JeM chief Masood Azhar claimed that the handler of the Pathankot operation had quit the organisation sometimes ago.

"Azhar disowns the JeM handler (to prove his innocence)," another source privy to the development told PTI.

He said the investigation agencies have been under "immense pressure" from Prime Minister Nawaz Sharif to thoroughly probe the matter and come up with "true facts" of the Pathankot incident.

Although the Counter-Terrorism Department (CTD) of the Punjab police had registered an FIR against the alleged attackers of the Pathankot airbase and their abettors, not a single person has been charged in this regard.

The FIR was registered in the CTD police station Gujranwala under sections 302, 324 and 109 of the Pakistan Penal Code, and sections 7 and 21-I of the Anti-Terrorism Act.

The FIR says Indian National Security Adviser Ajit Doval informed authorities that the four attackers had come from Pakistan and had "probably crossed the border adjacent to the Pathankot general area".

The NSA says the terrorists made phone calls to cell phones and belonged to a proscribed organisation.

Five terrorists and seven Indian army personnel were killed in a gun battle at the Pathankot airbase.

The attack occurred just days after Prime Minister Narendra Modi paid a 'surprise' visit to Sharif on his birthday on December 25 and the occasion of his granddaughter's wedding - a move that appeared to promise better ties between the two countries in future.

Adviser to the Prime Minister on Foreign Affairs Sartaj Aziz also confirmed that one of the mobile phone numbers linked to those who attacked the airbase had been traced to the JeM headquarters in Bahawalpur, some 400-km from Lahore.

JeM chief Azhar, who has been named by India as the mastermind of the airbase attack, had been under protective custody since January 14.

Aziz said that Azhar, along with a few other operatives of JeM, had been kept under protective custody and that some of the JeMs premises had been sealed.

He said action would follow against Azhar and others the moment evidence became available.

However despite the Pathankot visit of five-member JIT team of Pak Punjab government headed by CTD Additional Inspector General of Police (IGP) Tahir Rai, no progress has been made in the investigation so far.