Song Young-gil, former chair of the main opposition Democratic Party of Korea, on Friday denied allegations of illegal campaigning before a 2021 ballot where he was elected the party chairman, as well as separate bribery allegations.

The prosecution is now seeking criminal charges against the 60-year-old, who was a five-term lawmaker. He has not been indicted for the allegations.

Song said he would exercise his right to remain silent during the interrogation, in a show of resistance to what he called "politically motivated prosecutors."

"The prosecution's statement of fact based on its interrogation of a suspect would be inadmissible if a defendant denies the statement in court," Song told reporters as he appeared at the prosecutors' office in Seoul for interrogation.

He added, "It is of no use to defend myself from allegations against me. I would rather do so before court judges. ... I will remedy the miscarriage of justice in the courtroom."

His appearance comes eight months after the revelation that a total of 94 million won ($71,900) in cash was distributed to scores of party members through Song's aides in early 2021. Song in May 2021 won the party election by a narrow 0.59 percentage point margin. Prosecutors are looking into possibilities over whether Song had orchestrated the illegal campaigning.

Under the Political Parties Act, Korea criminalizes any money transfer as part of election campaigning within the party. Those offering or accepting the money through illegal campaigning are subject to imprisonment of up to three years or a 6 million won fine, while those who orchestrated the illegal campaigning will face tougher punishment of up to a five-year imprisonment or a 10 million won fine.

Rep. Youn Kwan-suk has been in custody for four months since August for his alleged involvement in illegal campaigning. In October, Song's former secretary, who was only identified by the surname Park, admitted to the charges that he violated the Political Parties Act.

Song is also facing separate bribery allegations. He is alleged to have asked an unidentified owner of a waste incineration plant based in Yeosu, South Jeolla Province, for 350 million won to be transferred to a political think tank, in return for the party's lobbying effort to the government for a plant expansion. The plant was later given the green light for the expansion plans.

Of the 350 million won, the prosecution reportedly identified 40 million won as a bribe.

The bribery allegation prompted another search and seizure of Song's residence in September, following one in April.

Song responded to the allegation Friday, saying he "was not aware of" the situation.

Song underwent voluntarily questioning by the prosecution on two occasions in May and June. At the time, he called on the prosecutors to stop investigating people around him and investigate himself instead. His proposals were denied by the prosecution.

Song stepped down from the chairman post in March 2022 after Democratic Party presidential candidate Lee Jae-Myung lost to Yoon Suk Yeol, who took office in May 2022. Lee, who later became a lawmaker, has been leading the party since August 2022.