Four current and former executives of one of the nation's major umbrella labor groups were arrested for making contact with North Korean spies overseas.

The Suwon District Court issued arrest warrants for the four suspects with links to the Korean Confederation of Trade Unions(KCTU) on Monday for violating the National Security Act.

In issuing the warrants, the court said the charges have been verified and the defendants pose a risk of flight and destruction of evidence in consideration of the seriousness of the charges.

The National Intelligence Service(NIS) and the National Office of Investigation(NOI), which conducted raids on the residences of the four in January, suspect they made contact with North Koreans at different times in Hanoi, Vietnam.

One of the current officials is also suspected of maintaining contact with North Korean agents for years, meeting agents three times between 2017 and 2022 in Cambodia's Phnom Penh and China's Guangzhou in addition to Hanoi.

The official allegedly exchanged orders and reports remotely on more than 100 occasions, including instructions to instigate anti-government sentiments in calling for the ouster of President Yoon Suk Yeol.