In a major breakthrough in a case related to a Khalistani module in Pune, the National Investigation Agency (NIA) has arrested absconding Khalistani terrorist Gurjeet Singh Nijjar from the Indira Gandhi International Airport here soon after he arrived from Cyprus where he was in hiding.

An NIA spokesperson said that the arrest was made on Tuesday. The NIA had registered a case on January 10 last year against accused Harpal Singh. During the investigation, it was revealed that Nijjar was the main conspirator in this case.

Nijjar, Harpal Singh and Moin Khan were active on social media platforms and had hatched a criminal conspiracy to revive Sikh militancy for the ultimate aim of formation of a separate state of Khalistan, the official said.

"It was also revealed that as part of the conspiracy for a separate Khalistan state, Nijjar, Singh and Khan used to post videos and images praising Jagtar Singh Hawara, a convicted accused in the assassination of former Punjab Chief Minister Beant Singh, besides uploading images and videos of Operation Blue Star of 1984 and pro-Khalistani content related to proscribed organisation Babbar Khalsa International (BKI) with the sole intention to motivate likeminded Sikh youth and others to join the Khalistan movement," the official said.

The official said that it was found that Khan, who was lodged in Delhi's Tihar Jail from 2013 to 2016, had developed contact with Jagtar Singh Hawara and had shown his willingness to work for him, also sharing his contact number with him.

"Subsequently, Khan sent a friend request to the Facebook ID 'Khalistani Jindabad Khalistan' from his Facebook account. By joining this Facebook group, Khan came in contact with Harpal Singh and Nijjar," the official said.

Nijjar motivated Khan by discussing about the alleged atrocities committed against the Muslims and Sikhs in India and convinced him to work for a separate Khalistan state, the official said.

The official also said that as part of the conspiracy, Nijjar directed Khan to purchase a pistol and ammunition in 2018 and to carry out their nefarious designs.

The NIA had filed a charge sheet against Nijjar, Singh, Khan and Sundar Pal Parashar on May 23 last year in a NIA special court.

Nijjar, a resident of Amritsar, left India on October 19, 2017 for Cyprus in Europe, following which a look-out circular was issued against him.

The official said that his transit custody shall be obtained and he shall be taken to Mumbai for further investigation.