The probe into the spy agency’s alleged evidence forgery is meandering along, hitting one unexpected obstacle after another.

On Saturday, a midlevel National Intelligence Service official identified by the surname Kwon attempted suicide in Hanam, Gyeonggi Province, after being questioned earlier in the day. Kwon is suspected of playing a part in the process of obtaining the forged Chinese immigration documents used in the case against Yoo Woo-seong.

Yoo, a former Seoul City official of North Korean-Chinese origin, is accused of spying for Pyongyang.

The NIS agent is the second individual implicated in the case to attempt suicide after the NIS collaborator, who is suspected of forging the documents. The collaborator, identified as Kim, has since recovered and is currently under arrest.

Kwon was found unconscious in his brother-in-law’s car, having burnt a coal-based fuel product in an attempted self-asphyxiation. Kwon is said to be unconscious and in critical condition at a hospital in southern Seoul, where he is being treated while guarded by the NIS.

Although the reason behind his suicide attempt is not yet known, Kwon is reported to have expressed strong discontent with the investigation.

Kwon, who serves as a vice consul general at the South Korean mission in Shenyang, China, was questioned by the prosecution on three occasions from Wednesday to Saturday.

During the most recent questioning, Kwon left the Seoul High Prosecutors’ Office midinterrogation after an argument over the prosecution’s allegedly forceful investigation.

“The prosecution is pushing the investigation in a particular direction, and the prosecution is causing discord within the organization (NIS),” a local daily quoted him as saying on Saturday. The 51-year-old agent is also reported to have said that the prosecution was framing NIS agents on his team as forgers. 

The prosecution, however, claims that there were no irregularities in its investigation.

In addition to suspects attempting suicide, the prosecution’s efforts are being hampered by NIS agents allegedly colluding on their answers despite the investigation moving higher up the ladder.

All NIS officials questioned so far, including an agent surnamed Lee who is immediately above Kwon in the chain of command, have said that they had no part in forging the documents.

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