The names of the three persons, hailing from Nepal, Bangladesh and Myanmar, surfaced during interrogation of the arrested suspected ISI agent Akhtar Khan, a senior officer of the STF of the Kolkata Police said.
Though the role of these three persons were yet to be established, Kolkata Police sleuths suspected that they acted as "information carriers" and smuggled in money through hawala channels.
Talking about why Akhtar's brother Zafar was arrested, the STF officer said that there were discrepancies in his statement during his interrogation.
It was learnt that Zafar, like his brother, had gone to Pakistan in the 1980s and after staying there for around 20 years returned to India.
Several documents, including an ATM card of a Pakistani bank, were also recovered from their Collin Street house, the officer said, but did not divulge the name of its holder.
According to a highly-placed source in the STF, the documents recovered from their Collin Street residence were "quite suspicious" containing defence-related information of the country.
