Ruling and opposition parties locked horns on Friday over allegations that late President Roh Moo-hyun disavowed the legitimacy of the de-facto sea border between the two Koreas in 2007, a claim which could influence December's presidential election.

The ruling Saenuri Party said it will call for a parliamentary probe to officially investigate the claims made by one of its lawmakers earlier in the week. Party officials threatened that if the main opposition Democratic United Party (DUP) ignores the request, it will push for a unilateral probe.

The conservative party said that if Roh actually made the remarks he seriously compromised the country's sovereignty during the inter-Korean summit meeting.

Rep. Chung Moon-hun, said earlier in the week that Roh met with late North Korean leader Kim Jong-il at around 3 p.m. on Oct. 3, 2007, and verbally promised to nullify the Northern Limit Line (NLL) that acts as the sea demarcation line between the two Koreas.

The lawmaker also said the president agreed to provide massive aid for the communist country, sympathized with efforts by the North to pursue a nuclear weapons program, and offered to remove all U.S. troops from Seoul and the neighboring regions.

Saenuri's spokesman Lee Cheol-woo said that if the DUP insists that the allegations are false, it has no reason to shy away from a probe that could prove them right.

The conservative party, in addition, claimed that right before the October 2007 summit the presidential office ordered the country's spy agency to conduct a review of possible fallout if South Korea no longer enforced the NLL. All this it claimed showed that Roh had made the remarks.

In response, the DUP made clear that Saenuri was engaging in old fashioned mud-slinging tactics to win votes and threatened to take legal action against those who are spreading lies. Party sources raised suspicions that Chung may have viewed classified diplomatic documents that are off limits to all but a few people.

Reflecting the party's resolve to end the debate, the DUP's presidential hopeful Moon Jae-in, who had come under pressure to explain his stance on the issue, said that he will take responsibility if Roh made the remarks.

Moon was chief of staff to the late president and was in charge of planning the summit meeting.

"If the remarks were made, I will apologize in the place of President Roh since he has passed away," the 59-year-old human-rights lawyer-turned-politician said.

He said that despite what has been said, he is confident that there could be no transcripts of the purported comments, because Roh and the North Korean leader did not have a secret meeting.

Moon said the suspicions raised by Chung were very grave so it should not be allowed to pass and the truth must be made public as soon as possible.

"According to the Saenuri lawmaker, the document is in the possession of the Unification Ministry and the National Intelligence Service, so these agencies should confirm or deny the existence of the document, and if it exists I would like to see it so as to make my judgment," he said.

He made clear that if the allegations turn out to be false, Chung and Saenuri's presidential hopeful Park Geun-hye need to be held accountable.

"Saenuri Party will have to face the judgment of the people if the claims made are lies," the candidate said.

Moon, however, maintained his party's stance that there is no reason for a parliamentary probe to take place on this matter.

Chung, meanwhile, stuck to his claims, and pointed out that they were made after a North Korean news briefing said in late September that the communique reached between Roh and Kim in 2007 was based on the premise that the NLL is unlawful and invalid.

The communist country also said that claims made by the Lee Myung-bak administration that the demarcation line must be guarded were based on ignorance.

"The North's comments clearly show that they know something about the NLL that the public in the South does not know," he said.

The lawmaker moreover said that both the Unification Ministry and the country's intelligence agency made clear through official letters that they could not confirm or deny the existence of copies of the transcript.

"This is not the same as saying there is no such document," Chung claimed. (Yonhap News)