SEOUL -- Former South Korean President Lee Myung-bak was questioned Wednesday over allegations of taking 11 billion won ($10.3 million) in bribes from corporations and institutions, including Samsung, Hyundai Motor, and the country's spy agency.
Lee is the fifth former head of state to face investigation during his or her term, raising the question of whether too much power in the hands of the president lays the seeds for wrongdoing and feeds persistent political volatility in the system.
Prosecutors suspect the 76-year-old businessman-turned-politician pressured Samsung to pay $5 million in 2009 to a U.S. law firm that represented an auto parts company called Das owned by his brother. Investigators believe Lee is the real owner of Das, and created slush funds worth 30 billion won through the company.
He is also suspected of taking 1.7 billion won of state funds from the National Intelligence Service. The NIS's annual budget of around 500 billion won is not subject to public oversight to ensure the secrecy of its operations.
Lee has denied the allegations, saying the investigation is politically motivated. He has argued that the investigation is rooted in the case of former President Roh Moo-hyun, who committed suicide in 2009 as he was being investigated over corruption under Lee's administration. Roh was a close friend of current President Moon Jae-in, who supported Roh at the time.
"I hope this is the last case in history," said Lee before entering the Seoul Central District Prosecutors' Office. "I feel painful and sorrowful to stand here. I am sorry to make people worry about my case while people suffer from poor economic conditions and the serious security situation surrounding the Korean peninsula."
Lee's summons comes a year after former President Park Geun-hye was grilled over allegations of bribery and abuse of power. Earlier this month, the prosecution demanded a 30-year prison term for Park. A ruling is expected next month.
The prosecution is considering requesting an arrest warrant for Lee if he denies the allegations under questioning. Should he be arrested, he would be the second former president behind bars on corruption charges.
Experts say repeated corruption scandals involving former presidents are a measure of the volatility of country's political system. The centralization of power around the president is seen as a factor Park's apparent abuse of power last year.
"The president enjoys too much power but takes little responsibility for what he or she does," said Shin Yool, a political science professor at Myongji University in Seoul. "We need to decentralize presidential power to resolve this problem in the upcoming process of revising the constitution."
President Moon is pushing to revise the constitution to change the political system, aiming to submit a bill by next week. The key point is the adoption of a U.S.-style limit of two, four-year terms for presidents, from the current single five-year term.
But the bill will not likely pass easily, as the opposition parties are unhappy about the proposed revision. The main opposition Liberty Korea Party says the National Assembly should lead the process, rather than the president. Constitutional revision requires more than two-thirds of the votes in the assembly.