"We have named Amir Zubair Siddiqui, a diplomat in the Pakistan High Commission based in Colombo in the case busted recently.
The FIR has his name," 'Q' Branch Superintendent of Police Sampath Kumar said.
He said the diplomat's name has been added to the FIR, "based on the statement of Thamim Ansari," who was arrested on Monday last by state intelligence while he was heading for Tiruchirapalli airport to take a flight to Colombo.
Twenty five CDs and photographs of various important installations in the state were reportedly seized from him. The diplomat is believed to have instructed Ansari to take visuals of defence establishments in India and pass it on to him, sources said.