By Jung Sung-ki
Staff Reporter

The main opposition Democratic Party (DP) called for an independent prosecutor to investigate a bribery scandal involving incumbent and former top tax officials, Friday, to uncover irregularities by President Lee Myung-bak and his key aides.

The move comes after Ahn Won-koo, a former official of the National Tax Service (NTS) imprisoned while awaiting trial for corruption, argued that Lee was involved in land speculation and secret accumulation of wealth before the 2007 presidential election.

The governing Grand National Party (GNP) denounced the DP's move as a political offensive to sabotage the passage of next year's budget, including financing for the revised Sejong City plan in South Chungcheong Province.

In an interview with DP lawmakers at a Seoul prison, Ahn claimed he had seen a document that proves Lee was the owner of land in Dogok-dong in southern Seoul.

This allegation ― that Lee, a former CEO of Hyundai Construction and Engineering, had bought land valued at 26.3 billion won under family members' names there ― was raised during the 2007 presidential campaign.

However, prosecutors said at the time that there was no proof to back the claim.

An independent counsel later concluded that the land had been bought by Lee's older brother Sang-eun and brother-in-law Kim Jae-jung. The two purchased the land in 1985 and reaped huge profits by reselling it to POSCO 10 years later.

If the allegation is proven true this time, the President could have violated a law that obliges public officials to report all their assets.

Cheong Wa Dae has made no comment on the issue.

``We won't sit idly by on this issue because it could be one of the biggest corruption scandals ever that compromises the national interest,'' said Rep. Park Joo-sun, a supreme council member of the DP. ``We demand that Cheong Wa Dae and the ruling Grand National Party (GNP) agree on naming an independent prosecutor to investigate the case.''

Last week, the Seoul Prosecutors' Office arrested Ahn for bribery. Ahn and his wife, Hong Hye-kyung who owns an art gallery, allegedly pocketed illegal profits by selling paintings to businessmen after promising to go easy on them during tax audits.

The prosecution also found that Ahn gave 300 million won to a close aide of then-presidential candidate Lee in 2007, who the DP alleges was Lee's oldest brother Sang-deuk, on behalf of his boss, then-NTS chief Han Sang-ryule.

Ahn claimed Han had pressured him to do this because he needed a total of 1 billion won to retain his office. Ahn said he was excluded from promotion because he turned down the demand.

Han stepped down from his role as NTS commissioner in January following allegations that he got the top tax job after bribing his predecessor, Jeon Goon-pyo, with an expensive painting.

On Wednesday, Han, who is staying in New York, dismissed Ahn's claims.

``When the appropriate time comes, I will explain everything about the accusations. I will also file defamation suits,'' he told journalists there. ``But for the time being, I have no immediate plan to return to Korea.''

DP legislators suspect the Lee administration has been lukewarm on summoning Ahn to uncover the truth, and questioned the ``abrupt'' arrest of Ahn who could disclose details of corruption cases that might be linked to those in power.

The opposition party alleges that Han might have a political connection with President Lee because the former tax chief initiated the tax audit against shoemaker Taekwang Industrial to investigate its links with the late President Roh Moo-hyun. Prosecutors later found that Taekwang CEO Park Yeon-cha gave slush funds to the family of Roh, who killed himself during the investigation.

Ahn said Han had telephoned Cheong Wa Dae to report on the progress of the tax probe into Taekwang.

gallantjung@koreatimes.co.kr