By Yi Whan-woo

The prosecution has launched an investigation into vote-rigging allegations in the election of the main opposition Democratic United Party’s (DUP) chairman early this month.

The Seoul Southern District Prosecutors’ Office said Wednesday a voter, identified as Kim, allegedly voted twice for Rep. Lee Hae-chan, 60, the elected chairman, during the leadership race.

The probe came after a member of the Young Liberty Union (YLU), a conservative civic group, filed a report to the prosecution that the female voter cast a ballot for Lee in both mobile and on-site voting at the national convention.

The DUP only allows one vote per person, and the YLU member, surnamed Chang, has been calling for a prompt investigation, according to the prosecution.

“Chang first made the claim to the Supreme Prosecutors’ Office, which handed the case over to us today and we’ll summon him to verify his allegation,” an investigator said.

The prosecution said it will also summon Kim, who allegedly confessed to Chang that Lee’s faction within the DUP pressured her to cast two votes.

“We have not decided how to expand our investigation, but if such claim turns out to be true, we will also look into Lee himself,” a prosecutor said.

Lee received 24.3 percent of mobile votes by citizens and on-site votes by party members during the chairmanship election from May 21 to June 9. Lee, a seven-term lawmaker, was trailed by Rep. Kim Han-kil with 23.8 percent and Rep. Choo Mi-ae with 14.1 percent.

The elected chairman had lagged behind Kim, a four-term lawmaker who served as culture minister, in the previous votes by party members in provincial regions, but reversed the race with support in the mobile vote.

Lee has taken charge of the party’s strategy for the Dec. 19 presidential election.

The prosecution said it will deal with the case prudently as the impact of the investigation could be a huge blow to the DUP.