Chinese security authorities have recently cracked down on several hundred Taiwan-related espionage cases and arrested a group of Taiwan residents suspected of spying.

In a special operation known as "Xunlei-2020", the authorities targeted the infiltration and sabotage activities of Taiwan spy intelligence agencies and busted a Taiwan spy network deployed by the agencies to the Chinese mainland.

According to a report by China Central Television on Sunday, Taiwan leader Tsai Ing-wen and DPP authorities have recently been colluding closely with foreign forces and have stepped up efforts to promote a series of "Taiwan independence" activities, challenging the "one-China" principle and undermining peace and stability across the Straits.

Taiwan's spy and intelligence agencies, acting as a tool for DPP authorities, have meddled with diplomatic relations between the Chinese mainland and other countries and have attempted to raise Taiwan's international position, jeopardizing national sovereignty, security and development interests, the report said.

Xunlei-2020 has helped safeguard national security and is another major effort targeting Taiwan intelligence agencies and DPP authorities, following an operation in 2018 codenamed Thunder-2018, it said.

In addition, a CCTV program revealed more details of a case in which a Taiwan resident, Lee Mengchu, was investigated for allegedly endangering national security by engaging in espionage work and intervening in Hong Kong affairs.

Lee, 48, was put under control in August 2019 by the Shenzhen national security bureau when he was about to return to Taiwan from Shenzhen, Guangdong province. He is a businessman in Taiwan and also serves as a director of a "Taiwan independence" organization called the Taiwan United Nations Alliance.

Media reports have shown that this organization has traveled all over the world to campaign for Taiwan to join the United Nations and network with overseas anti-China politicians.

According to the program, Lee's engagement in "Taiwan independence" activities dates back to 2001 when he was studying in New York. At that time, he often frequented a place called Taiwan Club, where he made acquaintances with separatist parties before joining the alliance in 2009.

In 2019, Hong Kong demonstrators kicked off months of protests against a now-withdrawn extradition bill. Taiwan separatist forces seized the opportunity to clamor for "independence" and supported violent demonstrations in the special administrative region.

CCTV said Lee was persuaded to head to Hong Kong to join the protests and made flyers that stand for "Hong Kong and Taiwan freedom" with a map that separated the two areas from the mainland with two different colors.

Lee arrived in Hong Kong on Aug 18, 2019. He actively participated in anti-China assemblies and sent pictures of himself back to Taiwan.

After his stay in Hong Kong, he learned from a source that a group of armed police were deployed to Shenzhen. Lee decided to travel across the border to photograph them, seeing this as another opportunity to show loyalty to the alliance.

He headed to Shenzhen on Aug 19, 2019, and wandered around Shenzhen Bay Stadium, filming and taking pictures of armed police, despite a cordon clearly stating that filming was not allowed. He then sent the materials back to Taiwan and hurried to the dock before being arrested.

Shenzhen police said Lee's pictures and videos depicted "military secrets" involving location, combat equipment and troop quantity, which could lead to the disclosure of combat capability and intention, seriously endangering national security.

"These people participating in these activities do not really care about Hong Kong people's safety or Hong Kong's freedom and democracy. They only want to gain some attention in Taiwan and earn some political assets for themselves," said a police officer with the Shenzhen national security bureau.