Air Force officer Arun Marwaha has been sent to police custody for five days.

Highlights Group Captain Arun Marwaha was honey-trapped by ISI: investigators

A senior Air Force officer had set up an internal investigation

Arun Marwaha, 51, has been sent to five days' custody

An Indian Air Force (IAF) officer has been arrested in Delhi on charges of espionage and passing on classified information to Pakistani intelligence agency Inter-Services Intelligence or ISI. Group Captain Arun Marwaha, 51, leaked information and documents to two Pakistani agents who chatted with him on social media pretending to be women, say investigators.The officer, posted at the IAF headquarters in Delhi, is a para-jumping instructor and was in charge of training elite Garud commandos. He has been charged under the Official Secrets Act and faces up to 14 years in jail. He was due to retire next year.Sources say after the officer befriended the ISI agents on Facebook - they had fake profiles as women - a few months ago and they started chatting regularly on WhatsApp. They allegedly even exchanged intimate messages. After gaining his trust, the agents asked the officer for classified documents. The officer shared them regularly on WhatsApp in return for obscene photos, according to sources. The information that he shared was reportedly on new agencies in the field of cyber warfare, space and special operations.A senior Air Force officer discovered the massive breach a few weeks ago and set up an internal investigation. When Marwaha's role was revealed, IAF informed the Delhi Police. After questioning him for 10 days, the counter-intelligence wing of the Air Force turned the case over to the police.

The officer was arrested on Thursday as he was walking into the Air Force headquarters with his cellphone, which is not allowed in the building. He has been sent to five days' police custody by a court.Investigators from IAF's counter intelligence wing are examining whether officer Marwaha was part of a larger espionage ring run from Pakistan, sources say.The IAF has not commented on the arrest but officials say Marwaha was indulging in certain "unwanted activities" through "unauthorised electronic devices".