The prosecution is said to have opted not to apply the National Security Act to the case involving alleged evidence forgery by the national spy agency, as the detention warrant for a key suspect went under review on Tuesday.

At present a National Intelligence Service collaborator and a mid-level spy agency official are in custody in connection to the case. Both men have only been identified by the surname Kim.

The suspects are alleged to have been deeply involved in providing the prosecution with forged Chinese immigration documents in its case against Yoo Woo-seong, a former Seoul City official accused of spying for North Korea.

The collaborator is suspected of having forged Chinese government documents under the direction of the NIS official.

NIS’ Kim, however, denied the allegations and said the collaborator simply informed him that he would secure relevant documents.

According to reports citing unnamed officials, the prosecution will not be applying the National Security Act to the suspects. Under the act, those found guilty of fabricating evidence with the intent to frame others for espionage can be sentenced to death, life imprisonment or a prison sentence of more than seven years.

Riled by the reports concerning the National Security Act, the main opposition Democratic Party stepped up its attack on the government.

“The case should not be scaled down nor cut short. The prosecution is picking up the pace but the public’s doubts in the investigation remain,” DP floor leader Rep. Jun Byung-hun said.

He added that applying only the Criminal Act to suspects was adding to the speculations that the investigation was being conducted in a manner favorable to the NIS.

“The prosecution’s responsibility is to investigate Nam and to uncover the truth. In addition, Nam’s immediate dismissal is the fundamental premise for a clear investigation.”

DP lawmakers on the parliamentary Legislation and Judiciary Committee backed up the party’s attack calling for the committee to convene on Wednesday, saying that related developments were undermining national security and diplomatic ties.

“There is a need to understand the problems of investigative and intelligence organizations’ illegal evidence manipulation, and to develop countermeasures,” the DP lawmakers said in a statement.

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