The accused, Moti Ram Jat, was actively involved in espionage activity and had been sharing classified information related to national security with the Pakistan intelligence officers (PIOs) since 2023, they said.
The agency has found that he was receiving funds from the PIOs through various conduits, officials said.
NIA arrested Moti Ram from Delhi and is interrogating him.
Moti Ram was remanded to its custody till June 6 by the special court at Patiala House Court, NIA said.