Prosecutors searched the offices of key aides of National Assembly speaker Park Hee-tae on Thursday in connection with an alleged vote-buying scheme during the Grand National Party’s 2008 leadership election.

The prosecutors are also said to be planning to question Park, but have yet to decide on how to proceed because of his position as National Assembly speaker.

In the raid, investigators searched and seized evidence from the offices of Park’s chief secretary for policies, Cho Jeong-man, and chief secretary for state affairs, Lee Bong-gun. In addition, the investigators also searched the National Assembly speaker’s ancillary office where a secretary works.

The three played key roles during Park’s campaign for the party leadership.

Cho, who has worked for Park for more than 20 years, was in charge of financial and organizational matters during the campaign, while Lee served in a public relations role.

Hahm oversaw the accounting during the campaign.

The investigators suspect that Cho and Lee are among those who gave orders to Koh Myung-jin and An Byung-yong.

Koh, a former secretary to Park, is thought to have been the man who delivered 3 million won ($2,600) along with Park’s business card to Rep. Koh Seung-duk.

An, chief of a district-level GNP council, is currently under arrest for his suspected involvement in a bribery scheme.

A member of Park’s campaign team, An is suspected of handing 20 million won to five members of district councils with instructions to bribe 30 GNP officials.

As the investigators delve deeper into the allegations, the suspected involvement of other lawmakers has risen.

The prosecutors have secured testimony that An instructed the district council members to give one vote to ex-GNP lawmaker Gong Sung-jin. As such, Gong’s former aide identified by the surname Kim was summoned and questioned by the prosecutors.

In the 2008 election, each representative was given two votes and the investigators suspect that Gong and Park colluded to influence the outcome of the vote. In that year Park was elected as the GNP’s chairman and Gong was made a member of the party’s supreme council.

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