He also said that Ahn Cheol-soo, former presidential contender for the party, is "unrelated" to the scandal and that the panel decided to disclose the tip-off.

"The panel made its best efforts in the verification," Kim added.

The People's Party made the revelation four days before the election and accused Moon of exerting influence on the hiring as a presidential secretary at that time.

Kim was one of the party members who went public with the disinformation in two press conferences, presenting as evidence an audio file and captured mobile chats the party had claimed to be from Moon's friend.

The tipoff turned out to have been concocted by Lee You-mi, now-detained former campaigner for then-presidential contender Ahn Cheol-soo, as she confessed to doctoring the evidence.

The prosecution accuses Kim of spreading false information in breach of the election law. They also believe that the election panel turned a blind eye to the possibility that the tipoff could be untrue and pressed ahead with exposing it.

The prosecution said they will also investigate the extent to which Kim and others in the election panel had communicated with the party's leadership about the tipoff.

On Sunday, they called in Kim In-won, then a vice head of the election panel, for questioning into the case. The prosecution has also arrested another party member, Lee Jun-seo, for suspected involvement in the case. (Yonhap)