The Delhi Police on Thursday detained an employee of the Pakistan High Commission for suspected espionage. Mehmood Akhtar was questioned at a police station in Chanakyapuri, Delhi's diplomatic enclave, for allegedly possessing highly-classified defence documents, NDTV reported. "On initial interrogation, the official said he is an Indian citizen and also showed a fake Aadhaar card," said Joint Commissioner (Crime) of Delhi Police Ravindra Yadav.

Investigators said Akhtar was detained after they received a tip-off. While the 35-year-old was released soon after his detention as he has diplomatic immunity, according to The Times of India, two men from Rajasthan – Maulana Ramzan and Subhash Jangir – were arrested for leaking the documents to him, officials said. Yadav said the police will soon arrest another spy identified as Shoaib in connection with the case.

Akhtar was reportedly part of Pakistani High Commissioner Abdul Basit's (pictured above) staff. Basit was summoned by the External Affairs Ministry and was informed by Foreign Secretary S Jaishankar that Akhtar had been declared persona non grata (an unacceptable or unwelcome person) for espionage activities, ANI reported. The Delhi Police said Akhtar has been asked to leave India.

However, Basit has denied India's accusations and has, instead, accused the country of manhandling a Pakistani staffer. He said the high commission "never engages in activity incompatible with its diplomatic status" and asked the Indian government to "ensure that such harassment does not happen in future".

According to the joint commissioner of police, Akhtar had been an officer in the Pakistan Army's Baloch regiment who was later hired by the Inter-Services Intelligence. He worked in the high commission's visa department, the official said, adding that those involved had been carrying out the espionage activities for at least 18 months, and their movements had been monitored for the past six months.

Documents recovered from the spies from Rajasthan included papers on deployment of defence personnel, maps of where Border Security Force officers had been stationed and visa-related documents. A report on the matter has been sent to the External Affairs Ministry's high commission staffer, and the crime branch has intimated Home Affairs Minister Rajnath Singh and Lieutenant Governor Najeeb Jung.

In November 2015, five people were arrested after a syndicate of spies associated with Pakistani intelligence was exposed. A few employees of the Pakistan High Commission had come under the radar after the operation.

Akhtar's detention comes amid strained relations between India and Pakistan, which worsened since the militant attack on the Army's camp in Kashmir's Uri sector.