Prosecutors raided the residence of an ex-aide to former main opposition Democratic Party(DP) leader Song Young-gil in their investigation into alleged bribery ahead of the 2021 party convention where Song was elected party chief.

The Seoul Central District Prosecutors' Office on Friday conducted the search and seizure as it probed the ex-aide, identified by the surname Lee, who reportedly handled scheduling and accounting for Song's campaign at the time.

The former aide reportedly also fine-tuned schedules and managed the activities of a group of lawmakers who supported Song, including a meeting in which a handover of cash allegedly occurred.

Prosecutors suspect that DP-turned-independent Rep. Youn Kwan-suk, implicated in the scandal, distributed envelopes each containing three million won to 20  lawmakers of the group.

The investigative agency is reportedly trying to obtain a list of people in attendance as well as the camp's accounting books to verify those who had accepted the bribery.