The lawmaker who was recently accused of plotting to overthrow the government had visited North Korea on two different occasions, the government said Monday.

Rep. Lee Seok-ki, a first-term lawmaker of the minor opposition Unified Progressive Party, is suspected of organizing an underground entity called the Revolutionary Organization with the aim of subverting the South Korean government and blowing up infrastructure facilities throughout the country.

Reports have said Lee traveled to North Korea to secretly meet with North Korean officials. Any such meeting could link the rebellion plot to North Korea.

"Records showed he was at the Mount Kumgang resort on March 31-April 1 in 2005 and again on March 16-18 of 2007," Unification Ministry spokesman Kim Hyung-suk said.

Kim said that Lee went to the scenic mountain on a package tour with members of CN Communications, an advertising company he manages.

The spokesman said that during the 2005 trip, the lawmaker was on parole after being released from prison. He had been imprisoned for pro-North Korean activities.

"Records show the ministry had consulted related organizations and none raised objections to the trip in 2005," the spokesman said.

The official pointed out that Lee went as part of a tour and was not required to report if he met any North Koreans while at the mountain resort. The official declined to speculate if the politician met North Koreans outside of the tour package. 

The ruling and opposition parties are expected to pass a motion on Tuesday at the earliest for Lee's detention.

Pyongyang has remained quiet on the incident, having only made short media reports last Thursday and Friday.

"The reports by the Korean Central News Agency and Uriminzokkiri were brief and claimed the allegations raised so far constitute a repression of the UPP," said one observer.

This contrasts with vehement reactions made by the North in the past when the South announced investigations into subversive activities involving the communist North.

Kim Yong-hyun, a professor of North Korean studies, said Pyongyang may not want to break up the detente generated by agreements to reopen the joint factory park in its border town of Kaesong and the family reunions set to take place this month for people separated by the 1950-53 Korean War. (Yonhap News)