When the ruling Grand National Party was holding a national convention to select its leader, rumors that candidates distributed envelopes containing cash invariably made the rounds. None of them had been vetted until recently, and few came out to acknowledge they had been offered cash during the convention.

But some of the rumors are most likely to be checked out this time, with one first-term lawmaker having said in public that he received an envelope containing 3 million won from a person close to a candidate. Presumably, the lawmaker, if he was telling the truth, could not have been alone in being targeted for bribery by candidates, each of them allegedly spending billions of won to buy votes.

Rep. Koh Seung-duk said he returned the money before the candidate was elected party chairman. He refused to elaborate. Nor did he say what prompted him to make the allegation, not during or immediately after the vote, but at a time when the party is in the process of reinventing itself ahead of the April general elections.

The money-for-votes allegation is rocking the ruling conservative party, with the scandal bringing back the memory of the “vanloads of cash” that its 2002 presidential candidate received from business concerns in illegal contributions. Its disclosure in late 2003 was one of the most serious crises the party had ever experienced.

Apparently fearful of such a backlash, the party was quick to begin damage control. On receiving Koh’s allegation, the party called on the prosecutors’ office to launch a criminal investigation into the case. Koh promised to say who the culprit is when summoned by prosecutors.

During the past four years, the party had three national conventions. Koh said that Rep. Hong Jun-pyo, who recently resigned from the post of chairman, was not the culprit, leaving either Rep. Park Hee-tae, now National Assembly speaker, or Rep. Ahn Sang-soo, Hong’s immediate predecessor, as the suspect. The two have denied bribing party members for votes ― a criminal offense that is punishable with up to three years in prison or 6 million won in penalties.

The party says it will clean up the mess as soon as possible. If it is to make good on its promise, it will have to withdraw membership from all lawmakers involved in the scandal. It will not suffice to deny them nominations for the upcoming elections.