South Korean President Lee Myung-bak 's son avoided indictment over his involvement in a controversial purchase of land for the president's post-retirement residence, prosecutors who led a month-long probe into the scandal announced Wednesday.

Instead, a team of special prosecutors said they have handed over tax records of the president's 34-year-old Si-hyung to the state-run National Tax Service for suspicions of possible imposition of gift tax.

They have indicted former presidential security chief Kim In- jong and two other officials of the Presidential Security Service, which jointly bought 462 square meters of land with Si-hyung last year for the residence, on charges of breach of trust.

The findings were announced after a 30-day investigation by the independent counsel, recommended by the main opposition Democratic United Party and begrudgingly appointed by the president who was pressured into scrapping his plan for the retirement home in an affluent neighborhood in southern Seoul.

Media revelations last year that the plot was purchased in Si- hyung's name sparked allegations that he violated South Korea's real estate law. The junior Lee was also suspected of misappropriating taxpayers'money by purchasing the land at a below- market price and letting the security service pay more.

The scandal has been the latest embarrassment for the president, whose closest aides and elder brother Sang-deuk are jailed for their involvements in a series of corruption scandals.

Both Si-hyung and Lee's brother Sang-eun were summoned by the prosecutors for questioning, and first lady Kim Yoon-ok submitted a written statement on her alleged involvement in the land deal.

The president on Monday rejected the prosecutors'request for extending the investigation by 15 days, citing its potential influence on the upcoming presidential election.

Before being elected to lead South Korea, Lee himself was mired in a financial scam that implicated his former colleague at an investment company called BBK.

The five-year tenure of Lee, who is immune from prosecution, ends early next year. He is constitutionally barred from seeking re-election.