The main opposition Democratic United Party on Tuesday demanded a reinvestigation of the 2010 illegal surveillance scandal, following a claim from a key suspect that the presidential office had directed its cover-up.

“The prosecution should re-investigate the case and get to the bottom of the suspicions that the Presidential Office was behind the illegal operation,” Rep. Kim Jin-pyo, the party’s floor leader, said during a party meeting.

The opposition politicians equated the case to the Watergate scandal in 1970s that ousted U.S. President Richard Nixon, saying the party will push for a probe by an independent counsel, if the prosecution does not move.

“This is President Lee’s Watergate. It has been revealed that the presidential office ordered (the illegal monitoring of a civilian), the prime minister’s office executed it and the prosecution covered it up,” Kim said.

The scandal erupted in 2010, entailing illegal spying by officials at the Prime Minister’s Office on a civilian who posted video clips critical of President Lee Myung-bak on his blog in 2008. The PMO officials destroyed their computers after prosecutors began a probe.

Suspicion was rampant at that time that it was part of a wider surveillance and sabotage operation against Lee’s opponents under direction of the presidential office.

The prosecution, however, closed its case, indicting only several PMO officials, citing a lack of proof linking the case to any of the presidential aides.

Lee In-kyu, head of the public ethics division at the PMO, and three of his staff received prison terms for illegal surveillance. Three others were convicted of destroying evidence and also got jail terms. They have appealed and are now awaiting decisions by the Supreme Court.

The case was brought back in the spotlight recently, when Jang Jin-soo, one of the PMO officials on trial, revealed that he acted on orders from the presidential office.

He disclosed an audio recording purportedly of a dialogue between himself and Choi Jong-seok, a former labor affairs staff member at Cheong Wa Dae.

In this dialogue, Choi apparently offers cash and life-long support to dissuade Jang from revealing the “whole truth.” The former presidential aide also says that the presidential office had a deal with the prosecution regarding the case.

Jang was convicted of destruction of evidence and was sentenced to eight months in jail, suspended for two years. The former official claimed that the presidential office ordered him to destroy the hard drive of his computer with a hammer or dump it in Han River. He also said the same office provided him with a mobile phone registered under a borrowed name to use when reporting to the presidential office.

The People’s Coalition for Economic Justice, a Seoul-based civic group, issued a statement Tuesday, urging an re-investigation into the case.

“The prosecution should now admit that its probe was insufficient and begin re-investigation immediately,” it said.

By Lee Sun-young (milaya@heraldcorp.com)