This combined photo shows four South Korean activists entering the Cheongju District Court, about 140 kilometers south of Seoul, to attend an arrest warrant hearing on Aug. 2 for allegedly taking orders from North Korea to stage anti-weapons protests. Yonhap

Four South Korean activists charged with espionage were found to have used a local online newspaper to disseminate N. Korean propaganda and to update Pyongyang about investigations against them, sources said Monday.

According to the sources, the activists used an online media website owned by one of them, a 47-year-old man surnamed Son, as a channel to glorify the regime.

The activists were recently arrested on espionage charges for allegedly taking orders from Pyongyang and staging a series of protests opposing Seoul's plan to procure U.S.-built F-35A stealth fighter jets.

They were allegedly ordered to promote the "greatness of the chairman," referring to North Korean leader Kim Jong-un, to different South Korean groups, especially the youth, through the newspaper.

The National Intelligence Service (NIS) and the National Police Agency (NPA) confirmed those orders in the USB flash drives seized during the raid in the activists' residences and offices in Cheongju, about 140 kilometers south of Seoul, in May.

The NIS reportedly identified 45 articles idolizing Kim Jong-un and North Korea published on the site up until June.

The evidence also showed that the activists swore their loyalty to Kim in 2018, promising to become "faithful warriors" for Kim who, they said, was working for the "unification of the Korean peninsula" and the "absolute victory of socialism."

After the NIS and NPA launched the investigation, the activists also reportedly used the local media to update the North of any developments.

According to the Cheongju District Prosecutors Office, the suspects were unable to use an encrypted program to communicate with Pyongyang after the May raid and seemed to have used newspaper articles to update the North with the ongoing investigation.

In June, the newspaper carried an article titled "North Korean agent Lee Gwang-jin is a ghost created by South Korean intelligence officials," apparently tipping off the North's United Front Department (UFD) that their illicit operation had been exposed. The UFD is known to be in charge of handling inter-Korean affairs and Pyongyang's espionage operations in the South.

Last Monday, prosecutors asked the Cheongju District Court to grant arrest warrants for the suspects, saying they were highly likely to keep informing the North of the investigation to help Pyongyang destroy evidence unless they are detained.

The court allowed the authorities to arrest three of the activists.

One of the activists, only identified as a 57-year-old, reportedly started working for North Korea in 2004, while Son began in 2010. When the other two allegedly became North Korea sympathizers remained unknown.

They, according to the investigators, have traveled often to China to meet North Korean agents and report their activities to benefit Pyongyang, such as anti-weapons movements, talks with ruling Democratic Party affiliates on inter-Korean affairs and the establishment of an underground organization to spread North Korean ideology here.

On Monday, Son reportedly claimed there is no underground organization and the NIS and the police manipulated the case to stage an anti-communism campaign. (Yonhap)