Republic of Korea's President Moon Jae-in speaks during a meeting of his senior secretaries at the presidential Blue House in Seoul, the ROK, April 12, 2021. (PHOTO / AP)

SEOUL – The Republic of Korea (ROK)’s presidential office on Friday dismissed opposition lawmakers’ calls for explanations on a relationship between President Moon Jae-in and three activists who were arrested on charges of coordinating with the Democratic People’s Republic of Korea (DPRK)’s agents.

The ROK activists were arrested on Monday on charges of violating the National Security Act by campaigning, under an order from a DPRK operative, against the ROK military’s plans to buy US stealth fighters, according to police.

READ MORE: DPRK warns against US-ROK drills, casts doubt on summit

Under usual procedure in the ROK, authorities have not identified the activists nor has the identity of their lawyers been disclosed.

Police and the National Intelligence Service (NIS) have also accused the three of receiving some US$20,000 from the operative.

The liberal Moon Jae-in has been keen to improve relations with the DPRK, saying both sides would benefit economically

Their mission included “underground organizations” to carry out pro-DPRK, anti-US movements, a police official said, declining to elaborate citing the investigation.

The Korean peninsula has been divided for decades and spy scares and scandals between the Cold War rivals have been common over the years.

The latest case sparked political uproar when the Chosun Ilbo newspaper, citing unidentified sources, said the activists had worked on Moon’s presidential campaign as special advisers on labor issues before he took office in 2017.

The Chosun Ilbo and other media outlets also said the activists had met a senior lawmaker of Moon’s ruling Democratic Party to discuss possible projects with the DPRK.

Police, the NIS and the Cheongju District Court, which issued an arrest warrant for the activists, could not be reached for comment on the Chosun Ilbo report.

ALSO READ: DPRK, ROK 'in talks over summit, reopening liaison office'

The main opposition People Power Party described the case an “espionage scandal” and demanded that Moon and the Democratic Party clarify their relations with the activists.

A spokesperson at Moon’s office dismissed the assertion that the activists had worked for Moon, saying in a statement it was “not worth mentioning.”

A spokeswoman at the Democratic Party said it had no comment.

The liberal Moon has been keen to improve relations with the DPRK, saying both sides would benefit economically.

In the first sign of easing of tension for months, the two Koreas last week restored hotlines which the DPRK cut a year ago as ties came under stress.