The dispute over the transcript of the 2007 summit between President Roh Moo-hyun and North Korean leader Kim Jong-il has taken a new turn as allegations surfaced that the document was illegally leaked to some ruling party lawmakers before the December presidential election.

The allegations were first put forward by Rep. Park Beom-kye, a lawmaker of the main opposition Democratic Party. Park claimed that the Saenuri Party’s presidential campaign team had planned to use the controversial summit minutes as a kind of trump card.

As evidence, the DP legislator presented a voice recording of a conversation involving Kwon Young-se, one of the top officials of the Saenuri campaign headquarters who currently serves as Seoul’s ambassador to China.

During the conversation with his acquaintances, which was held in December, Kwon talked about a “contingency plan” under which the party would disclose the summit minutes to turn the tables should the tide of the election shift against its candidate, Park Geun-hye.

He was also quoted as saying that the ruling party would disclose the document in the event it won the election.

Separately, Saenuri lawmaker Kim Moo-sung, who led Park’s campaign, reportedly said at a meeting of the party’s senior officials Wednesday that he obtained the document during the election campaign.

He was quoted as saying that “the content (of the document) was so shocking that my hands trembled.” He also reportedly said that although he asked Won Sei-hoon, then the director of the National Intelligence Service, to disclose the minutes, the spy chief refused to cooperate.

But Kim denied he had obtained the summit transcript during the election campaign. He said the document he read was produced by his own staff based on what he heard from Rep. Chung Moon-heon, a Saenuri lawmaker who perused the summit dialogue script while serving as a presidential secretary.

Now, the DP suspects that behind the illegal leak of the document to Saenuri lawmakers was the NIS. The party’s lawmakers need to investigate these suspicions when they launch next month a parliamentary probe into the allegations that the spy agency meddled in the December election.

The ruling party should clarify what happened in regard to the new allegations that they obtained and used the summit transcript in the election campaign. It also needs to cooperate with the opposition party in conducting the parliamentary probe into the spy agency.

The two parties should use the investigation as an opportunity to reform the NIS and prevent its interference in politics. They should not let the precious opportunity slip by while they engage in futile political wrangling.