TAIPEI - Taiwan's high court on Thursday (April 26) upheld the conviction of a former Chinese student on charges of recruiting spies for Beijing, saying his actions had posed serious threats to the island.
The decision comes as cross-strait tensions rise, with China accusing Taiwan of moves towards formal independence.
The self-ruling democratic island has never formally declared a split from the mainland and Beijing still sees it as a renegade province to be brought back into the fold, by force if necessary.
Zhou Hongxu, 31, who graduated from a top Taiwanese university in 2016, will serve out the 14-month jail term handed down by a lower court after his appeal was rejected.
"The defendant's actions posed serious threats to our territory and national security, given the disharmony and even hostile situation between the two sides," said high court spokesman Chiou Jong-yi.
The court had shown leniency in sentencing since Zhou had confessed and his attempt to recruit spies had been unsuccessful, he added.
Taiwan and China have spied on each other since 1949 when nationalist troops fled to the island and set up a separate government after losing a civil war on the mainland to communist forces.
Taiwan's National Security Bureau chief Peng Sheng-chu has said that Chinese espionage is "more serious than before".
Local media report up to 5,000 people may be spying for China on the island.
Zhou was instructed by officials in Shanghai in late 2015 to recruit "Taiwanese government personnel and other people of influence" while he was studying and working in Taiwan, according to Thursday's ruling.
Zhou had attempted to recruit a man working in the Taiwanese government from August 2016, promising payment of at least US$10,000 (S$13,000) per quarter before the man turned him in to local authorities.
China last week staged live-fire drills in the Taiwan Strait - the narrow waterway separating the Chinese mainland from Taiwan - following weeks of naval manoeuvres in the area.
Chinese officials said the drills were to safeguard Beijing's territorial sovereignty and issued a fresh warning Wednesday that they would take further actions if "Taiwan's independence forces were to continue their reckless course".
Taipei accused China of being "extremely irresponsible" and said it was threatening peace in the region.
Beijing is deeply suspicious of President Tsai Ing-wen's traditionally pro-independence Democratic Progressive Party and has cut off official communication with Taipei since she came to power in 2016 as she refuses to accept that the island is part of "one China".
Chinese officials have also railed against Premier William Lai in recent weeks who has repeatedly declared his personal support for Taiwan's independence.