Kim Dong-a calls on Han Dong-hoon to explain how he obtained investigation records

Democratic Party of Korea lawmaker Kim Dong-a appeared before police Sunday after filing a criminal complaint against independent lawmaker Han Dong-hoon over allegations that he leaked investigation materials related to Justice Minister nominee Kim Seung-won.

Yeongdeungpo Police Station in Seoul questioned Kim as the complainant in the case.

Han had earlier claimed that prosecutors investigating the so-called "new drug clinical trial approval lobbying" allegations against the nominee had come under outside pressure and issued Kim a suspended indictment. Han then publicly released an indictment plan the prosecution team had drawn up at the time.

Kim filed a complaint with the Korean National Police Agency's National Investigation Headquarters on Monday, arguing that Han's disclosure of the document constituted a breach of official secrets. The case was assigned to Yeongdeungpo Police Station.

Speaking to reporters before her questioning, Kim said Han had claimed he received the materials through a whistleblower, but that evidence obtained through search and seizure is not something a third party outside prosecutors, defendants or defense counsel can obtain.

"Police must thoroughly investigate who handed Han Dong-hoon this vast trove of investigation records," she said, adding that she would "root out the rotten foundations of a politicized prosecution that has privatized investigative agencies and made a mockery of the rule of law."

Meanwhile, Yeongdeungpo Police Station is also investigating a separate complaint filed against nominee Kim Seung-won on charges including violations of the Political Funds Act and the Anti-Graft Act in connection with the clinical trial approval lobbying allegations.