The presidential office must be on edge as it faces two high-profile investigations at the same time. One concerns the cyberattack last October on the website of the National Election Commission while the other is about illegal surveillance of a civilian.

On Monday, an independent counsel started a probe into the NEC website attack that took place on Oct. 26, the day Seoul mayoral by-election was held. A massive distributed denial-of-service attack brought the election watchdog’s website down, making it difficult for voters to find the locations of their polling stations.

A DDoS attack was also launched against the website for Park Won-soon, the independent candidate who won the mayoral poll.

In January, prosecutors identified two young men as the culprits of the unprecedented cyberattacks ― an aide to the then National Assembly Speaker Park Hee-tae and his accomplice who was an aide to Rep. Choi Ku-sik, then a ruling party member but now an independent lawmaker.

The investigation outcome was discredited as it failed to clear the suspicions that there might be someone behind the two suspects. Prosecutors simply said they could not find any evidence that a powerful figure had been involved.

To dispel the public’s suspicions, the ruling and opposition parties demanded that a special counsel be named for reinvestigation. President Lee Myung-bak responded by appointing Park Tae-seok, a veteran lawyer, to lead an independent counsel consisting of some 100 prosecutors and investigators.

The team is required, among other things, to go deeper into the matter and determine if there was someone who had set up the attacks and told the two suspects to execute them.

Hacking the NEC’s website to stop people voting is a direct challenge to democracy. The two suspects probably would not have dared to commit such a reckless act had they not been offered a big reward by someone they trusted.

While looking for the mastermind or masterminds behind the cyberattacks, the special counsel team also needs to look into the allegations that the presidential office had attempted to cover up the case and intervened in investigations by police and prosecutors.

Kim Hyo-jae, the then senior secretary for political affairs to Lee, is suspected of leaking investigation information to Rep. Choi. He informed the lawmaker of the arrest of his aide one day before police announced it.

Furthermore, Kim was also found to have talked frequently over the phone with the head of the National Police Agency and Choi while the case was investigated. But prosecutors did not bother to question Kim.

The independent counsel should ferret out those who attempted to distort the democratic process and bring them to court. Park needs to remember that the public is closely watching his investigation team.

The presidential office is also being investigated for its alleged attempt to cover up the illegal surveillance of a civilian by officials of the Prime Minister’s Office in 2008. Prosecutors wrapped up their probe in 2010 but were forced to reopen it recently following bombshell revelations by a former PMO official who was indicted for destroying evidence of surveillance.

This week, Yim Tae-hee, a former chief of staff for Lee, surfaced as a key figure following prosecutors’ finding that the unidentified official of the Ministry of Employment and Labor who delivered 40 million won to Jang Jin-su, the whistle blower, in August 2010 was Lee Dong-gul, an aide to Yim.

We still do not know where the money came from or whether Yim ordered Lee to deliver the money to Jang. But suspicions of Yim’s involvement in the alleged cover-up attempt have deepened with the identification of Lee’s involvement.

Yet prosecutors’ questioning of Yim is unlikely to happen anytime soon, given the slow pace of their investigation.

On Tuesday, Jang unveiled another recording of a phone conversation, this time with an official of Korea Gas Corp. The recording further implicated the presidential office in the cover-up attempt. The Kogas official told Jang that he had arranged a job placement for Jang at the request of the Blue House.

Jang also claimed that he heard from a PMO official in January 2011 that his case was reported to the president. Cheong Wa Dae dismissed the claim, saying it was merely Jang’s side of story. Prosecutors need to speed up their probe. There are too many loose ends to tie up.