TAIPEI: A Taiwanese admiral has been questioned over his alleged involvement in one of the island’s worst espionage cases, officials said on Monday, as concerns mount over Chinese infiltration of the military.

Defence ministry spokesman David Lo announced the admiral has come under investigation, but declined to provide details.

The Taipei-based Apple Daily said the admiral, whom it identified as Hsu Chung-hua, has been transferred from his position as the commander of fleet based in Penghu, an island group in the middle of the Taiwan Strait.

According to reports, the investigation is linked to the September arrest of three senior military officers suspected of leaking secrets to China, considered to be one of the most serious breaches in the island’s history.

One of the officers arrested in the raid was Chang Chih-hsin, formerly a commander in charge of political warfare at the navy’s METOC (meteorology and oceanography) office, which keeps highly classified maps and charts.

Military experts say that China could learn more about the operation of Taiwan’s submarines if it obtained such information.

The latest probe has spurred concerns that despite eased tensions across the Taiwan Strait, China has not reduced its hostilities towards the island.

“As more ranking officers have been involved in such espionage cases over the last few years, we are afraid that China has infiltrated various levels of the military,” legislator Tsai Huang-lang from the leading opposition Democratic Progressive Party (DPP) told reporters.