Intimate chat on social media with unknown "women", who later "turned out to be" an ISI agent, and suspected passing on sensitive information has landed an Air Force officer with just one more year in service in the police net.

Arun Marwaha (51), a para jumper instructor in charge of training the elite Garud commandos and posted at the Indian Air Force (IAF) headquarters, was arrested by Delhi Police on Thursday after the counter-intelligence apparatus is claimed to have found his involvement in passing on information to the ISI officer, official sources said on Friday.

Marwaha, who has 2,000 jumps to his credit, has never met the ISI agent, who pretended to be a woman, but allegedly passed on information on WhatsApp by copying documents using his smart phone at the Air Force Headquarters, sources claimed - mobile phones are not allowed at the Air Force headquarters.

The officer is learnt to have been honey-trapped by the ISI agent using two fake Facebook profiles in the name of Kiran Randhava and Mahima Patel, they said.

They started regularly chatting on WhatsApp and is also claimed to have shared intimate messages and making Marwaha share his own nude pictures, sources claimed.

After he fell into the trap, sources said, he was made to exchange sensitive information from the headquarters. Marwaha allegedly photographed the documents and passed it on to the ISI agent. He allegedly shared the information in return of obscene photos.

Sources said, technical surveillance mounted on Marwah raised red-flags and was detained for questioning by the Air Force authorities. Once his alleged role was established, Delhi Police was informed, which arrested him.

The Indian Air Force's counter intelligence wing is examining whether Marwaha is part of a larger espionage ring.

 Sources said the ISI might have noticed that Marwaha has been very active on Facebook and other social media platforms. He used to regularly post photographs and videos of his work and family gatherings.

A Delhi court has sent him to five-days custody of Delhi Police's Special Cell.