Javed Shameem, Deputy Commissioner of the Detective Department of Kolkata police, said Desai has been booked under various sections of the Foreigners Act and has been remanded in judicial custody till February 24.

“He is a Pakistani national and has no valid papers. We are looking into his antecedents,” said Shameem.

Desai was planning to sneak into Bangladesh from where he could have returned to Pakistan. The police traced Desai after he made repeated calls on the cellphones of former Army man Shailesh Jadhav, who was arrested by the Pune police on February 15 for his alleged links with the ISI. The police had seized three mobile phones and some classified documents carrying sensitive information about the Army establishments from Jadhav.

Unaware of Jadhav’s arrest, Desai was scheduled to meet him in Kolkata. “We had informed the Kolkata police about Desai’s presence in the city after tracing him through his call records,” said Inspector Bhanupratap Barge of the Crime Branch. Officers said Jadhav had received Rs 50,000 from Desai in three instalments. Police have also recovered an e-mail in which Jadhav has allegedly told an ISI official that he can provide them with some sensitive information. Jadhav, who worked as clerk in the armour corps, was court-martialled in 2002 in Jodhpur in a misappropriation case. Sentenced to a two-year term, Jadhav spent a year at the Yerwada Central Prison, where he met Desai.

After fleeing from jail, Desai stayed at Jadhav’s residence in Satara for a few days. He then went to Belgaum (Karnataka) on a truck, and then arrived in Kolkata via Hyderabad. Police have also detained two truck drivers who had taken him to Belgaum.