Behrampore, Nov. 26: Suspected ISI agent Aufan Ukil was brought under tight security to the district intelligence branch office here early on Monday for interrogation. Ukil, an air force employee, was arrested from his Pune base on Thursday following the confession of the four other “agents” arrested in the district on November 17.

Inspector-general of police (south Bengal) N.R. Das and his deputy, D.P. Tarenia, are grilling Ukil in the presence of the four ISI “agents” — Ziauddin Biswas, his wife Ismatara, brother-in-law Hasan Habib, and Ghulam Murtaza — arrested from Jalangi and Domkol.

In between the interrogation sessions, Das and Tarenia visited Durlabherpara village in Jalangi, home to Ziauddin and Rinku Ahmed, another alleged member of the ISI ring in custody. They have also held a meeting with the officers of Jalangi police station and reviewed the situation.

Ukil was brought here from Calcutta in a four-car convoy and lodged in the branch’s lock-up. His stay here has been shrouded in secrecy with police superintendent Birendra refusing to comment on his whereabouts. Birendra had to go to Calcutta to formally take custody of Ukil from the air force police, sources said.

Since Ukil is a defence personnel, police will have to hand him over to the air force for prosecution. The sources said it was not clear when he would be sent back to military custody.

Acting on information gathered from the four arrested “agents”, police picked up Rinku last Thursday along with two ex-servicemen, one from Nadia and another from Jalangi. On the same day, a sepoy of the Mahar Regiment, Nazrul Islam, was arrested by military intelligence and whisked away to his regiment headquarters in Madhya Pradesh to face court martial.

Ziauddin and the three others will have to be produced in court on November 30.