A key figure in an espionage case involving a former Seoul city official tried to kill himself on Wednesday, creating a major setback for the investigation.

The witness, only identified as ethnically Korean with Chinese nationality, is accused of giving the National Intelligence Service forged immigration documents regarding a former Seoul official suspected of spying for North Korea.

Investigators said the man slit his neck with a knife at a motel in Seoul, after being questioned by the prosecution.

“His condition is critical. (Doctors say) it isn’t a life-threatening injury but we have to watch out for aftereffects from his wound,” Yoon Gap-keun, head of the prosecution’s crime squad, told local media.

Before the incident, the man sent the investigators a text message about his suicide attempt, Yoon said.

Questions have been mounting over the case of Yoo Woo-seong, the 34-year-old former Seoul government official who was indicted last year for allegedly using his post to pass on the personal information of some 200 defectors to Pyongyang.

After a local court cleared Yoo of his espionage charges, prosecutors appealed with a higher court for the submission of Chinese immigration records allegedly forged by the witness.

The documents in question show that Yoo entered North Korea on May 27, 2006, and left through China on June 10, 2006.

But the case faced a reversal when the Chinese Embassy in Seoul called the documents “fabricated,” sparking criticism of the prosecutors’ office and the country’s legal system as a whole.

The National Forensic Center officials also said the seals on the NIS’ immigration documents differed from those submitted by Yoo.

Signaling a greater commitment to the case, the Seoul Central District Prosecutors Office launched a special investigation team to examine the authenticity of the immigration records. 

By Suk Gee-hyun (monicasuk@heraldcorp.com)