Taiwan army corporal arrested on suspicion of selling brigade exercise data to China

Taiwan's military counter-intelligence officers and prosecutors have arrested a corporal from the army's 542nd Armored Brigade on suspicion of selling military exercise material to people working for China, United Daily News reported on 12 October Taipei time.

The paper said the Ministry of National Defense's Military Security Command, working with prosecutors and investigators, recently went to the brigade's base in Hukou, Hsinchu County, and detained a corporal surnamed Lin. He is suspected of taking material from the army's Lu Sheng brigade-against-brigade exercise and selling it to people on the Chinese side for more than NT$400,000.

Ministry denies drill link

Replying to reporters on the evening of 11 October, the defence ministry denied that the case was connected with the Lu Sheng exercise and said no exercise information had leaked, according to United Daily News. The ministry said the recent action grew out of an espionage case reported by service members three years ago, and that it was continuing to identify and arrest everyone involved.

Unnamed sources quoted by both outlets gave a different account. They said the corporal served in a support company of one of the brigade's battalions rather than a combat unit, and that the material he sold came from last year's Lu Sheng 1 exercise, which he had kept instead of destroying it as regulations required. One insider told Formosa Television that, because he was not in a combat unit, the damage from the leak was likely limited. Neither outlet said exactly what the documents contained.

An army general told Formosa Television that Chinese intelligence services had been trying to learn how Taiwan's ground forces are changing their tactics, and that after the Lu Sheng 1 leak the army declared this year its year of rooting out spies. Under that campaign, the people who manage classified material, and not only those who leak it, can be held responsible.

A drill built to test new tactics

Lu Sheng is the army's annual brigade-level combat test, which replaced older exercises in which brigades from Taiwan's three western army corps faced each other. In the first edition in October 2025, the 542nd Brigade from Hukou played the defending force against the 234th Mechanized Infantry Brigade over seven days and six nights. It was the first time the drill made wide use of blank ammunition, drones and the TAK smartphone-based command system recently adopted from the US military.

This year's Lu Sheng 2 runs from 14 to 23 October and pits the northern 269th Brigade against the southern 564th Brigade for ten days and nine nights. Formosa Television said it will also be the first time M1A2T tanks and new drones are tested together in the exercise.

The arrest adds to a string of espionage cases involving serving and retired Taiwanese personnel this year. If the ministry's account holds, the case shows investigators still working through a network first reported years ago; if the unnamed sources are right, it means material from Taiwan's main ground-force combat test reached China.