Justice Minister Hwang Kyo-ahn apologized Thursday over a recent conflict between senior prosecutors in charge of investigating a high-profile election meddling scandal involving the state spy agency.

The apology came after a senior prosecutor, who had headed a prosecution team probing the scandal before being dismissed, quarreled with the Seoul Central District Prosecutors' Office chief, Cho Young-kon, during a nationally televised parliamentary meeting, by accusing his boss of impeding the investigation.

Cho rejected the claim, saying that the prosecutor, Yoon Seok-youl, was removed from the team for failing to report to his bosses.

"I am sorry and offer my apology to all the people for shameful things happening within the prosecution," Hwang said in a press release, adding that a thorough investigation will be carried out so that no doubt will be left behind.

The prosecution team probing the case further claimed that it has received pressure from the Ministry of the Justice to soft-pedal the case, escalating the controversy over the ministry's alleged attempt to play down the scandal.

In South Korea, the prosecution is under the supervision of the ministry.

The scandal centers on allegations that the National Intelligence Service (NIS) launched an online smear campaign to sway public opinion in favor of President Park Geun-hye ahead of last year's presidential election.

The investigation appeared to come to a close after prosecutors indicted key suspects a few months ago but regained traction after fresh findings suggested the alleged operation was much more extensive than originally thought.

The new discoveries by state prosecutors showed that the alleged operation was not limited to comments on major Internet bulletin boards but extended to Twitter, with NIS agents allegedly posting nearly 55,000 incriminating messages.

The main opposition Democratic Party demanded Park apologize, claiming the government attempted to cover up and minimize the scandal. The party also demanded Justice Minister Hwang step down.

"There are constant political controversies even though the result of the case has not yet come out," Hwang said. "I believe that this is not advisable." (Yonhap News)