A Taiwan court has convicted a former presidential aide of spying for China and three others who were also employed by the ruling Democratic Progressive Party (DPP).

One of the men worked in the office of then Foreign Minister Joseph Wu who now serves as the national security chief.

The court handed the men jail terms of between four to 10 years for leaking state secrets. The ruling said the espionage was carried out ?over a very long period of time? and involved sharing ?important diplomatic intelligence?.

Beijing claims democratically-governed Taiwan as its own, and the two have been spying on each other for decades. But Taipei claims Chinese espionage has intensified in recent years.

Of the four men sentenced on Thursday, Huang Chu-jung, a former assistant to a Taipei councillor, received the longest jail time: 10 years. Prosecutors had initially sought sentences of up to 18 years.

All four of them were charged in June, a month after they were expelled from the DPP.

According to the court, Huang had instructed a foreign office staffer to obtain information from Wu, then the foreign minister. He then wrote reports using this information, and sent it to Chinese Communist Party intelligence using encrypted software.

The foreign office staffer, Ho Jen-chieh, was sentenced to eight years and two months in jail.

Huang was also accused of working with another ex-DPP staffer, Chiu Shih-yuan to collect more information. The court heard that Chiu sourced information from Wu Shangyu, who was an aide to Lai Ching-te, the current president.

Wu served as Lai?s aide when he was the VP and then again for a short while after he became president in 2024. Wu was accused of passing on details about Lai?s itineraries during his travels.

Huang received almost NT$5m ($163,172; ?122,203) from the Chinese government, the court said, while Chiu was paid more than NT$2m.

?The information they spied on, collected, leaked and delivered involved important diplomatic intelligence?which made our country?s difficult diplomatic situation even worse,? said the court on Thursday.

These are just the latest in a string of espionage convictions as Taiwan ramps up efforts to find alleged Chinese spies on its soil.

In 2024, Taiwan?s National Security Bureau said 64 people were prosecuted for spying for China. That is a marked increase compared to previous years ? between 2013 and 2019, there were 44 espionage cases registered by Taiwan?s Ministry of Justice.

Espionage allegations have been levelled against several high-ranking Taiwan officials in recent years, including an ex-air force colonel who in 2023 was jailed for 20 years for running a military spy ring for China.

Taiwan?s relationship with China has become the subject of a deeply polarising debate. On one side is Lai?s DPP which is more outspoken against China and is seen as being pro-independence, and on the other is the Kuomintang (KMT) party, which has always been friendlier with China, and encouraged more dialogue.

The DPP accuses the KMT of being used by Beijing to pedal its influence ? while critics of the ruling party and President Lai say he is cracking down on the opposition under the guise of targeting ?pro-China? sympathisers.

This has been playing out as China reiterates its claims over Taiwan, testing its naval and air defences with regular incursions.

President Lai has often spoken out against China as a danger to Taiwan, calling it a ?foreign hostile force?.

Beijing, in turn, has repeatedly criticised him, calling him a ?destroyer of cross-straits peace?. (BBC)

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