The accused, identified as Mohammed Hamim Mondal, was arrested from Purba Bardhaman district on Friday and brought to Kolkata for questioning, Inspector General (STF) Gaurav Sharma said.

Addressing a press conference, Sharma said the investigation had established Mondal's links with Pakistan-based handlers and that he was allegedly working at their behest.

'The chief minister was one of the targets'

"The chief minister was one of the targets. Hamim had been assigned by Pakistan-based handlers the task of keeping a watch on the CM's movements. He was asked to gather information on the places the chief minister could remain unguarded," Sharma said.

According to the STF, Mondal had also planned to infiltrate the recent students' protest at Delhi's Jantar Mantar after procuring a police uniform.

"Besides that, several police officers and politicians were also planned to be targeted," Sharma said.

The officer said preliminary investigations indicated that, apart from Adhikari, several police officers and political leaders were on the radar of the alleged terror module.

STF arrests alleged associate

In a related development, the STF on Friday arrested Arpita Sarkar, described as Mondal's associate and girlfriend. Investigators alleged the two conspired to honey-trap the son of a West Bengal minister of state, abduct him and extort money from the family.

"Our investigation has revealed a specific plan to lure the minister's son into a honey-trap, followed by kidnapping and blackmail. The conspiracy was directed by Pakistan-based handlers. We are probing the precise role of each accused and whether others were involved," a senior STF officer said.

According to investigators, the duo allegedly sought to cultivate personal relationships with influential individuals to obtain sensitive information on the instructions of Pakistan-based handlers linked to the Shahzad Bhatti gang.

International SIM cards recovered

The STF said it recovered international SIM cards issued in the United Kingdom and Mexico from the accused.

"The SIM cards are suspected to have been used for encrypted communication with handlers operating from abroad and to facilitate the strengthening of sleeper cells and the terror network in different parts of the country," Sharma said.

The investigation also found that Mondal was allegedly radicalised through social media before coming into contact with Pakistan-based operatives linked to the Shahzad Bhatti group.

"During the investigation of his mobile phone and social media chat history, we have found some very serious information. He was in touch with several Pakistan-based handlers through encrypted platforms such as WhatsApp and Telegram," Sharma said.

The STF said Mondal was also in contact through encrypted messaging platforms such as Element X and Session, after first connecting with the alleged handlers on Instagram.

Investigators identified the handlers by the aliases 'Rana', 'Uzair', 'Abid Jatt 333' and 'Hamad', whom the STF alleged are linked to the Pakistan-based Shahzad Bhatti gang involved in radicalisation, narco-terror activities and extremist recruitment.

Probe began with honey-trap inputs

An STF officer said the investigation was launched after intelligence inputs suggested a plot to extort money from a senior politician by targeting his son.

"A few days ago, we received information about a plan to extort money from a senior politician from Howrah and abduct his son through a honey-trap. We were told that an organisation was behind the conspiracy. That led us to a social media handle from Sahibganj, which was being operated by one Arpita Sarkar," the officer said.

The STF said its investigation into Sarkar's social media account eventually led officers to Mondal. According to Sharma, the two had known each other for four years after first connecting on Instagram before meeting in person.

Investigators are examining whether Sarkar was used to lure potential targets as part of the alleged honey-trap operations.

Sharma said further investigation is underway to establish the full extent of the alleged terror network, identify other members of the module and trace its cross-border links.

"The matter is extremely sensitive, and we cannot disclose more," the IG said, adding that more arrests could follow.