The largest opposition Democratic Unified Party on Sunday urged the prosecution to investigate whether the presidential office had ordered the police to conceal important evidence that could identify the mastermind of the cyber attack on the National Election Commission website during the Oct. 26 by-elections.

“If Cheong Wa Dae is revealed to have been involved in the attack against the constitutional institution, the president should be impeached,” said Rep. Ooh Che-Chang, calling for a tougher probe into the case.

Rep. Kim Yoo-jung warned the prosecution that lawmakers would appoint special prosecutors should the investigation be carried out sloppily.

This came a day after Cheong Wa Dae’s official denial of its involvement in the cyber attack, which had been suggested by weekly magazine “Hankyoreh 21.” It reported that Cheong Wa Dae officials called the National Police Agency on Dec. 9 to manipulate several points of the investigation report.

The article claimed: “The Presidential office and the ruling party did not want the police to disclose that their people were involved in the crime. A high-ranking Cheong Wa Dae official made a last minute call to the NPA leadership and shared ideas on the case conclusion.”

The Seoul Central Prosecutors’ Office said last Wednesday that a former assistant to National Assembly Speaker and GNP lawmaker Park Hee-tae surnamed Kim sent 10 million won each to an aide to GNP lawmaker Choi Gu-sik surnamed Gong and an IT firm operator before the Oct. 26 by-election. The money is believed to have been payment for the cyber attack.

The investigators also said that Gong, Kim and a low-ranking Cheong Wa Dae official identified as Park met on the eve of the election in downtown Seoul, where Gong has reportedly confessed to the plot.

The meeting between the three was omitted from the Dec. 9 police report, which concluded that the hacking was independently orchestrated by Gong.

After the prosecution’s revelations, the police said they did not think Kim and Park had ordered or assisted in the hacking. A police official said they have not made Park and Kim’s names public for the sake of their “human rights.”

Rep. Park Young-sun of DUP claimed that the NPA leadership concealed details of the case to protect the administration.

NPA Commissioner-General Cho Hyun-oh on Friday held a press briefing and claimed that he also suspected Kim and Park but his subordinates deleted the information from the press release.

“I thought Park and Kim were related to the case, or at least worth investigating. But Hwang Wun-ha, who overlooked the investigation, insisted that Gong was the sole perpetrator of the crime. I will be damned if I have tried to manipulate investigation records,” Cho claimed.

He admitted to have talked with Cheong Wa Dae officials.

“I told them that my team found Kim irrelevant to the case. There was no order taken from the presidential office,” he said.

The attack on the NEC website reportedly hindered younger voters from finding polling booths and casting their ballots since many voting booths had changed from the previous election. Younger voters generally are more liberal in their voting habits. The NEC said it had received complaints that people gave up on voting because they could not gain access to information about the changed locations.

By Bae Ji-sook  (baejisook@heraldcorp.com)