Seoul prosecutors on Monday said they had indicted two working-level officials of the National Intelligence Service in relation to the spy agency’s alleged evidence fabrication, but stopped short of accusing its bigwigs.

The announcement effectively wrapped up a monthlong open investigation into allegations that the NIS forged Chinese immigration records to charge a North Korea-born former Seoul city official with spying for Pyongyang. The indictments came some two months after the Chinese Embassy in Seoul revealed that the documents were fake.

An official of the NIS surnamed Lee was indicted without physical detention for allegedly instructing other agents to forge the documents, the Seoul Central District Prosecutors’ Office said while announcing the final results of the investigation.

Lee In-chul, an NIS official who is serving as consul at the South Korean mission in Shenyang, China, was also charged for his alleged role in the document fabrication.

But the prosecution said it had come to the conclusion that the evidence forgery was not a part of a large-scale operation conducted by the spy agency’s leadership. They acquitted NIS chief Nam Jae-joon along with two prosecutors who were probing the case.

“The accused NIS officials said the top-ranking officials were not briefed on how the evidence was procured, and the investigation results are in keeping with their claims,” the prosecutors’ office said. They added that prosecutors had no knowledge of the fabrication, and instead made an effort to verify the documents by contacting Chinese officials.

Prosecutors also said they would not press charges against a veteran NIS agent surnamed Kwon for health reasons. Kwon, who served as the deputy consul general of the Korean mission in Shenyang, tried to commit suicide while being questioned by the investigators and is believed to have sustained serious brain damage.

The opposition party lawmakers berated the prosecution’s announcement, saying the investigators deliberately belittled the importance of the case to protect the leadership of the NIS.

“(Today) will go down in history as the prosecution’s day of shame. They have publicly revealed themselves to be slaves of the authorities,” opposition party lawmakers on the parliamentary legislation and judiciary committee said in a joint-statement.

They also urged President Park Geun-hye to clarify her position on the alleged evidence fabrication.

Yoo Woo-sung, a 34-year-old defector who had been accused of the spying charges, held a press conference and said it was clear that the NIS had orchestrated the forgery.

Later in the day, deputy NIS director Suh Cheon-ho offered to resign to take responsibility for the evidence fabrication. Suh, who is in charge of anti-communist investigation, made a public apology and said he feels "infinite" responsibility for the actions of his subordinates.. 

President Park promptly accepted his resignation, according to the presidential office. 

The four-year-old spy case was reopened earlier this year when the Chinese embassy in Seoul confirmed that documents the NIS submitted to prove the spy allegations against Yoo were forged.

Yoo had been accused of collecting information on some 200 defectors in South Korea and sending it to the North.

After he was acquitted of the espionage charges in August 2013, the NIS submitted immigration papers that supposedly proved Yoo had traveled to North Korea.

Yoo claimed that the documents had been fabricated, and suspicion arose that the NIS had faked the evidence to aid the prosecution’s efforts to prove that Yoo was guilty of spying.

Last month, prosecutors indicted an NIS agent and a Korean-Chinese collaborator for their suspected involvement in the forgery.

By Yoon Min-sik (minsikyoon@heraldcorp.com)