Prosecutors have indicted a lawmaker in an investigation into alleged bribery ahead of the main opposition Democratic Party's(DP) leadership race in 2021 that resulted in the election of Song Young-gil as party chief.

The Seoul Central District Prosecutors' Office indicted without pretrial detention DP-turned-independent Rep. Lee Sung-man on Wednesday, on charges of violating public election and political party laws.

Lee, one of up to 20 sitting lawmakers accused of having taken a cash envelope containing three million won, or around two-thousand-300 U.S. dollars, from Song's camp, is the first to be indicted over the related charge.

He is also suspected of providing one million won to Lee Jung-geun, former DP deputy secretary general, and ten million won to Kang Rae-gu, another camp member, in March 2021, as off-the-books campaign funds.

Meanwhile, the prosecution appealed an earlier Seoul court ruling that ordered a two-year prison term for DP-turned-independent Rep. Youn Kwan-suk to two years in prison for his role in the alleged bribery, and sentencing of one year and eight months for Kang.