President Park Geun-hye made a rare public apology Tuesday over intelligence agents' alleged evidence forgery.
"Regrettably, wrong practices of the NIS and holes in its management system have been revealed. I feel sorry for causing concern to the people," Park was quoted by her aides as saying during a Cabinet meeting, a day after prosecutors indicted two officials of the National Intelligence Service involved in the scandal.
"The NIS must make excruciating efforts to overhaul itself to make sure this kind of incident won't repeat itself. Should there occur any case of it losing people's trust again, I will take strong measures to hold it accountable."
Park warned of severe consequences should the NIS become involved in similar developments in the future. Park also said that the NIS must transform itself to regain the public's trust.
NIS Director Nam Jae-joon also offered an apology earlier in the day for the incident that undermined the public confidence in the country's evidence-based legal prosecution systems as well as the spy agency's role.
"As the (NIS) chief, I feel wretched and responsible for some NIS employees being indicted for forging evidence," Nam said.
Nam went on to say that the spy agency's investigative practices would be reviewed and the NIS would set up a task force for reforming old practices. Nam also said that scientific investigative methods would be introduced and structural reform would be implemented to bolster the NIS' functions concerning North Korea.
While apologising for the scandal, Nam also emphasised the importance of the spy agency, highlighting potential and past provocations by Pyongyang.
"I implore the people to give the NIS the chance to establish new foundations (as a spy agency). Again I apologise for worrying the people, and as the NIS chief I would take responsibility in preventing such occurrences in the future."
The apology follows the conclusion of the prosecutors' investigation.
On Monday, the prosecution indicted two midlevel NIS officials in connection with forging evidence against Yoo Woo-seong. In addition, deputy NIS director Suh Cheon-ho resigned, taking responsibility for the developments.
The prosecution, however, determined that the prosecutors who used the forged evidence were unaware of irregularities in the documents they submitted to the court, prompting criticism from the opposition bloc.
Yoo, a former Seoul City official of North Korean-Chinese descent, is accused of spying for Pyongyang. In repealing the lower court's acquittal of Yoo, the prosecution used forged Chinese government documents allegedly provided by the NIS.
Nam's apology, however, has done little to appease the opposition parties that have been at odds with the NIS since the 2012 presidential election.
"(The party) urges the president to dismiss Nam. The New Politics Alliance for Democracy once again declares that Nam's ridiculous apology is nothing more than making a fool of the people," NPAD floor spokesman Rep. Chyung Ho-joon said.
"The NPAD has decided in today's general meeting to submit a resolution for Nam's dismissal if a decision from the president or Nam's resignation is not forthcoming."
As the main opposition presses its attack, the issue has now been taken up by the parliamentary Legislation and Judiciary Committee.
At the committee meeting on Tuesday, lawmakers opened fire on Minister of Justice Hwang Kyo-ahn, accusing the prosecutors' office of being incapable.