Former President Lee Myung-bak did not play any role in the alleged Internet smear campaign by state agencies during last year's presidential election, his ex-press secretary said Friday, rejecting long-standing accusations made against the previous head of state.

The denial comes after state bodies like the National Intelligence Service (NIS) and the military's cyber warfare unit were found to have conducted extensive online smear campaigns against the main opposition candidate ahead of the December poll.

The prosecution has so far found that NIS agents posted nearly 44,000 online messages on blogs and Twitter, many of them intended to sway public opinion in favor of then ruling party candidate Park and against Park's rival candidate Moon Jae-in.

Announcing its interim probe results, the military prosecution said on Thursday the chief of the cyber warfare unit and his 10 subordinates uploaded about 286,000 messages online ahead of the election that were politically charged or against liberal political factions.

Under current law, public officials have the duty to maintain political neutrality.

"Former President Lee was not linked to the online campaigns by state agencies," Lee Dong-kwan, who served as the chief presidential press secretary, told a live radio program. "The head of state never knows and reacts to such an issue in such great details."

"The incident may have started during the term of the Lee government, but it has become a political dispute between the ruling and opposition parties (under the current administration)."

Lee served as South Korea's president from 2008 to February

this year.

The alleged smear campaign has been a bone of contention in the National Assembly, with the main opposition Democratic Party (DP) boycotting parliamentary meetings and demanding a special probe into the scandal.

The opposition party has long argued the spy agency's smear campaign, orchestrated by Lee and Park, has led to Park's election

victory in last year's tight race.

The DP, meanwhile, accused the military prosecution of misleading the election scandal probe on Friday, calling again for an independent investigation into the case.

"The probe failed to find the cyber command's connection with the NIS and presidential house," said Kim Han-gil, head of the Democratic Party, during a senior party members' meeting. "The chief of the cyber warfare unit has unfairly been made a scapegoat, while those who are really responsible have been excluded from the probe."

Rep. Jin Sung-joon of the DP said that the cyber warfare unit has sharply increased the number of its staff shortly before the presidential campaign last year, citing it as evidence that the unit has been mobilized to join the online smear campaign.

"The military's probe result that holds the cyber warfare unit's chief as the sole culprit is nonsense," Jin said. (Yonhap News)