A team led by special counsel Lee Kwang-bum raided Cheong Wa Dae's Presidential Security Service (PSS) at a third-party place in connection with the presidential retirement home deal that critics say misused taxpayer money, officials said Monday.

At a training institute of the country's financial regulator located near the presidential office in central Seoul, five members of the special counsel team began at 2:00 p.m. to search and seize relevant data and proof randomly submitted by the PSS, they said.

It marks the first time in South Korean history that the presidential office Cheong Wa Dae has come under a raid by any investigative authority.

In a related development, the team said that President Lee Myung-bak's wife Kim Yoon-ok will be questioned in written form, instead of being summoned or interrogated, over her role in the alleged irregularities by providing her stake in a private house in Nonhyun-dong in southern Seoul as collateral to help her son take out a 600 million won (US$542,000) bank loan.

The special counsel team weighed the options of a written or face-to-face questioning and selected the indirect questioning method for the first lady, balancing the need for both investigation and protocol, the officials said.

"Investigators generally search and seize (data) by force after presenting a warrant," assistant special counsel Lee Chang-hoon said during a press briefing before the raid.

"We cannot actually take that course in this case. That is why (we) discussed the third-party site," he added.

The unconventional raid comes after the presidential office repeatedly snubbed the team's request to hand over crucial data and information needed for the investigation over allegations that the president's only son, Lee Si-hyung, and the PSS used public funds and violated real estate laws when they jointly bought a plot of land last year for the retirement residence, which was to be built in Naegok-dong on the southern edge of Seoul.

The cost was allegedly not shared evenly, with the PSS paying too high a price for the site for security facilities, at the expense of taxpayers.

The team demanded that the office submit an original copy of a promissory note that the 34-year-old Lee Si-hyung claimed he wrote before borrowing another 600 million won in cash from his uncle, Lee Sang-eun, to fund the purchase, officials said.

The team also asked the presidential office to reveal the identity of a Cheong Wa Dae official who allegedly prepared Lee Si-hyung's written statement that was provided to prosecutors in May of this year, they added. The presidential office, however, has not responded.

Other relevant data, such as a demolition contract for a building on the land that reportedly listed President Lee as a contractor, have not been submitted as well, they added.

The team obtained the warrant from a local court on Friday for the unprecedented raid, officials said. The court, however, rejected the search and seize warrant for an official residence of Cheong Wa Dae, where Si-hyung claimed he had stored the money. (Yonhap News)