Two Pakistan High Commission officials were caught spying on Sunday after an operation by Military Intelligence (MI) found the men would visit Indian defence personnel as "businessmen" to secure information for "news reporters", triggering a demarche by the Narendra Modi government.
Both Abid Hussain and Mohammad Tahir have been declared persona non grata and expelled from India.
An official statement of the Ministry of External Affairs (MEA) said that two officials of the High Commission of Pakistan in New Delhi were apprehended for indulging in espionage activities.
Pakistan's Charge de Affaires was issued a demarche, in which a strong protest was lodged with regard to the activities of the officials of the High Commission of Pakistan against India's national security, the government said.
Sources said that out of the two, Hussain (42), working as an assistant in the Department of Trade in Pakistan High Commission, was an operative of Pakistan's spy agency, ISI and is from Punjab province of Pakistan.
While indulging in espionage activities, he told Indian defence personnel that he was from Amritsar.
His colleague, an upper division clerk in the high commission, Tahir (44), who is from Islamabad, would accompany him on the espionage missions to gather information for "news reporters".
The Indian government has declared both the officials persona non grata "for indulging in activities incompatible with their status as members of a diplomatic mission and asked them to leave the country within twenty four hours".
The two would pay Rs 25,000 for every exchange of information and expensive gifts such as Apple iPhones. They were paid via phone wallet application such as Paytm.
Both were in the commission for the last two years, sources said adding that the duo were driven around by Javed Akhtar (36), a resident of Mianwali in Pakistan's Punjab, who has also been arrested.
The two officials had been on the radar of the Indian agencies for their suspicious activities including attempts to contact and lure service personnel for espionage, sources said.
Delhi Police's Special Cell and the Intelligence Bureau assisted MI in the operations.
The law enforcement agencies, who apprehended the two officials, recovered some incriminating documents, Rs 15,000 and two iPhones from them. Of the two iPhones, they were to give one to their informants.
Sources said after they were caught, both Abid and Tahir admitted to be in communication with many other persons for gathering information.
The Ministry of External Affairs, in its statement,described the activities of the officials "inimical to India" and "incompatible with their diplomatic status".
( With inputs from IANS )