New Delhi: A 39-year-old Pakistani working for spy agency ISI has been arrested here with "incriminating documents" on defence matters, police said on Tuesday.

The spy, identified as Kamran Akbar alias Attar alias Asif Hossain from Karachi, was caught on the night of February 13 from Chelmsford Road near the New Delhi railway station for procuring sensitive defence documents.

"Presently he was residing in Kolkata and arrived here on February 13 morning to collect the incriminating documents which were to be sent to his handlers in Pakistan. We have recovered from him the secret, sensitive documents related to (Indian) defence affairs," said Deputy Commissioner of Police (Crime) Ashok Chand.

Chand said that after collecting the documents, Akbar was to board Poorva Express for Kolkata the same night, but was arrested after a tip-off. Akbar, who left studies in 1990, came to Kolkata in 1992 on a valid Pakistani passport to meet one of his relatives and stayed there with his uncle Mohammed Salim.

Later, he, along with his uncle and his uncle's associate Ashraf Khan, went to Goa, where they indulged in robberies. However, they were caught in their second attempt and arrested. Akbar was released in 1996 and came back to Kolkata.

With his Pakistani passport having expired, he arranged a fake Indian passport in the name of Asif Hussain and went back to Pakistan.

In 2004, he was reportedly recruited by the Inter-Services Intelligence (ISI) agency after they came to know that he had stayed in India and had acquired an Indian passport.

"He was motivated by the Pakistan military to work for them on being provided adequate compensation. He was trained in tradecraft knowledge about Indian military ranks, orbat, formation signs, TAC numbers -- codes to be used for communication, surveillance and anti-surveillance measures, internet, email chatting and some lessons in Hindi," added Chand. 

Chand said that Akbar was especially given Delhi as his target area and was tasked to cultivate defence personnel. He used to get funds through hawala and remittances from abroad were also made to his bank account.   Reaching Kathmandu from Dhaka in 2007, he was provided a driving license of Sikar in Rajasthan and USD 400, Chand said.

Abkabr then illegally entered India from Nepal and reached Kolkata. Based in Kolkata, he was spying and even married a local woman in 2009.

"He is the father of two children and also has a business of garment selling," said Chand. An Indian voter ID card, PAN card, driving license, Indian passport and an account in a government bank were recovered from Akbar's possession.