Prosecutors launched an investigation into alleged election fraud including double voting in the leadership race of the main opposition Democratic Party earlier this month.

The Seoul Southern District Prosecutors’ Office said Wednesday it will be investigating the case submitted by Jang Ki-jeong, head of Young’s Liberty Union, claiming there was fraud during the DUP’s leadership election between May 21 and June 9.

Jang claimed that a 20-something voter identified as Kim voted twice in the election, once through a mobile vote and again at the on-site delegate vote.

“We plan to call in Jang soon to look into his accusation and also investigate Kim’s personal data,” an official of the prosecutors’ office said.

Jang also reportedly claimed that Kim’s double voting could have been tacitly supported by an associate of DUP Chairman Lee Hae-chan. Lee came out the winner in the weeks-long race, beating his runner-up Kim Han-gill by winning 24.3 percent of votes compared to Kim’s 23.8 percent.

The prosecutors said they will be looking into whether there was any intentional double voting and how it may have influenced the outcome.

The DUP had earlier explained that the double voting in question was an administrative error and that there was no additional case of double voting based on internal review.

The DUP denounced the probe as “political oppression” and claimed the prosecutors were lining up behind the ruling Saenuri Party’s Park Geun-hye in the lead up to the presidential election.

By Lee Joo-hee (jhl@heraldcorp.com)