Prosecutors investigating a cash bribery scandal connected to the 2021 leadership election of the main opposition Democratic Party(DP) on Friday indicted a key figure in the case on charges of bribery and violating the Political Parties Act and the Political Funds Act.

Kang Rae-gu, a former standing auditor at the Korea Water Resources Corporation, is the first to be indicted in the probe that kicked off on April 12.

Kang is accused of colluding with former DP chair Song Young-gil and DP-turned-independent lawmakers Youn Kwan-suk and Lee Sung-man to deliver a total of 84 million won to sitting lawmakers and various other figures to help ensure Song's win in the inter-party election.

Separately, Kang is also suspected of receiving three million-won bribes from a businessperson in September 2020 in return for favors related to a Water Resources Corporation plant facility project.