An investigation into Korea’s intelligence agency has come to a halt following the attempted suicide of a key suspect, with the note he left behind bringing the investigation and the prosecution’s integrity into question.

The National Intelligence Service official, identified by the surname Kwon, attempted suicide on Saturday after being questioned for the third time in connection with the agency’s alleged attempt to frame Yoo Woo-seong for espionage using forged evidence.

Yoo, a former Seoul City official of North Korean-Chinese descent, is accused of spying for Pyongyang. Although he was initially acquitted, the prosecution appealed using Chinese immigration documents provided by the NIS. The documents, however, were later proven to be forgeries.

As the deputy consul general of the South Korean diplomatic mission in Shenyang, China, Kwon is suspected of having been involved in obtaining the forged documents.

Kwon, who denies all allegations against him, is reported to have claimed in his suicide note that the prosecutors’ office tried to blame the NIS, even though it was aware that Yoo was a North Korean agent.

In the note, which has not yet been disclosed to the public, Kwon reportedly apologized to NIS chief Nam Jae-joon for failing with his duties and claimed that the spy agency was being shaken by pro-North Korean forces in the South.

As Kwon’s suicide attempt hampers the investigators’ efforts to delve deeper into the case, the main opposition Democratic Party is continuing its attack against the NIS and the prosecution.

“Although the NIS is trying to scale down and distort the case using the suicide attempts of NIS officials and by playing the media, the prosecution’s probe on the body (of the case) is moving slowly,” DP spokesperson Rep. Han Jeoung-ae said.

Saying that what the public wants is an investigation into Nam, Han accused the prosecutors’ office of being incapacitated by Cheong Wa Dae and the NIS.

“It seems that it is difficult to expect (the prosecutors’ office) to recover the public’s trust and protect justice. A special counsel investigation is the only answer.”

Yoo is now being investigated on an unrelated case in which he is accused of failing to disclose his Chinese nationality in order to receive the state subsidy for North Korean defectors. The North Korean defectors’ group that lodged the criminal complaint against Yoo also filed a complaint against his sister for perjury. Yoo’s sister initially told the investigators that he was a North Korean spy, but retracted the statement during his trial.

By Choi He-suk  (cheesuk@heraldcorp.com)