Rep. Lee Jae-myung, leader of the main opposition Democratic Party of Korea, has been named a suspect in an investigation into illicit transfers of money to North Korea in 2018.

This makes Lee, who is already facing separate trials over corruption controversies from his time as head of Gyeonggi Province and the city of Seongnam, a possible defendant in yet another criminal case.

According to prosecutors in Gyeonggi Province’s Suwon, Lee is suspected of having played a major role in paying North Korean authorities some $3 million via underwear maker Ssangbangwool with the aim of arranging a trip to North Korea. As governor of Gyeonggi Province, which borders North Korea along the west of the border, Lee had pushed for exchanges with the North as one of his main projects.

Prosecutors have charged Lee with third-party corruption, which could mean up to five years in jail and 10 years of suspension from holding public office.

In March, then-Gyeonggi Province Vice Gov. Lee Hwa-young was indicted for his suspected involvement in the provincial office’s money transfers to North Korea.

The Democratic Party leader has so far denied all suspicions, telling reporters on Tuesday that his being booked by prosecutors in the investigation was “baffling.”

Lee, who narrowly escaped an arrest warrant earlier this year, said in a meeting last month that he would give up his immunity from arrest as an incumbent lawmaker if he finds suspicions sought by prosecutors to be “just.”

He has consistently characterized criminal investigations targeting him as a “politically motivated vendetta” by the current administration under President Yoon Suk Yeol, who he ran against as the main rival Democratic Party candidate in the election last year.

The Democratic Party suspects another request for an arrest warrant for Lee could head to the National Assembly before the regular session kicks off in September. To issue an arrest warrant for a sitting lawmaker, the court must first obtain majority consent of the Assembly under the Constitution.

With the general election to fill the Assembly less than a year away, anxiety is building within the Democratic Party about Lee -- who has been mired in multiple legal battles -- continuing to head the party.

One Democratic Party lawmaker on condition of anonymity told The Korea Herald that Lee was “ill-fit” to lead the party to victory in the upcoming election.

“He would be too busy responding to summons by prosecutors and attending court sessions to mind party business. His own political future will be murky if he were to be found guilty in any one of the several ongoing cases,” the lawmaker said.