Arun Selvarajan allegedly routed his information via Skype and Viber to his Pakistani handlers.
The National Investigation Agency (NIA) on Friday filed a charge sheet in a Chennai court in a case of alleged espionage and attempts to carry out sabotage activities in India at the instigation of Pakistan.
The chargesheet was filed at an NIA court against Thameem Ansari, a suspected operative of Inter-Services Intelligence (ISI), now on bail and a Sri Lankan national, Arun Selvarajan, besides three others who are their handlers in Pakistan and suspected to be based in Sri Lanka.
"The offences against the accused include those under Unlawful Activities [Prevention] Act, IPC and Official Secrets Act," Public Prosecutor for NIA cases, CSS Pillai told PTI.
Raising funds for terrorist act, conspiracy (Sections 17,18 Unlawful Activities Act), sedition, criminal conspiracy (IPC, 121 A, 120 B), penalty for spying (Section 3, Official Secrets Act) are among the major charges.
Also, Arun Selvarajan faces charges under the Passport Act for violations and Narcotic Drugs and Psychotropic Substances Act for possession of ganja, he added.
While Ansari is the first accused, Arun, arrested on September 10 last is fifth accused while the second, third and fourth accused are handlers.
Tagged as "Thammeem Ansari case" by the NIA, Arun Selvarajan was arrested as part of this case in September last for his alleged involvement in espionage activities at the instigation of Pakistan, the NIA had said at the time of his arrest.
Ansari was arrested in September 2012 and probe against him was initially done by 'Q' Branch state police and later it was transferred to the NIA in 2013.
The chargesheet was filed on Friday, the 175th day from the date of arrest of Arun Selvarajan just ahead of the expiry of 180 day deadline for its filing.
A total of 140 witnesses have been cited, 127 documents and over 100 materials including maps, laptops and mobile phones have been marked.
The chargesheet, which runs into 4010 pages, details how the duo were indulged in espionage activities, did conspiracy and attempted to plan and carry out sabotage at the behest of Pakistan and how they accessed sensitive installations.
Among other places, the accused visited port premises in Chennai, Nagapattinam, Mallipattinam, and witnessed an Indo-Japan joint coast guard exercise.
The probe was conducted by NIA DIG Ravishankar, senior officer Rama Seshadri and Superintendent of Police, L Kumar.
A preliminary chargesheet was filed by the NIA in October last against Zahir Hussain, Siva Balan and Mohammed Saleem in another case involving ISI spy modules.