ANKARA

South Korea's impeached President Yoon Suk Yeol on Saturday attended a court hearing to fight investigators' request to extend his detention and explain the legitimacy of his short-lived martial law decree in December.

A Seoul court is set to rule as early as Saturday night on a request by the country's Corruption Investigation Office for High-Ranking Officials (CIO), which is seeking a warrant to formally arrest Yoon over accusations of insurrection, Yonhap News reported.

The CIO requested a detention warrant on Friday to extend their custody of Yoon for up to 20 days.

Yoon will be the country's first sitting president to be formally arrested if the investigators' request is granted.

Footage aired on multiple local broadcasters showed vehicles with the arrested president aboard arriving at the Seoul Western District Court.

Yun Gap-keun, one of Yoon's legal representatives, told reporters that Yoon made the decision to attend the court hearing to explain the legitimacy of the martial law declaration and restore his tarnished reputation as well.

The CIO is currently leading a joint investigation with the police and the military over whether Yoon's martial law declaration amounted to an attempted insurrection.

Yoon's lawyers, however, have said the anti-corruption agency does not have the authority to investigate such allegations.

After charging Yoon with "leading an insurrection and abuse of power," the anti-graft body told the court that Yoon should be arrested due to the gravity of the crime and the risk of recidivism.

Yoon was arrested on the second attempt by a joint team of investigators led by the anti-graft body on Wednesday.

Held at the Seoul Detention Center, he was questioned by investigators for more than 10 hours on Wednesday but reportedly remained silent on charges of insurrection and abuse of power over his short-lived martial law declaration.

A court Thursday rejected Yoon's appeal to review the legality of his detention.

In a related development, two senior officials of the Presidential Security Service appeared for police questioning Saturday over allegations that they led efforts to block investigators from Yoon.

Kim Seong-hoon, acting chief of the PSS, and Lee Kwang-woo, head of the agency's bodyguard division, arrived separately at the National Office of Investigation's headquarters in western Seoul for questioning.

Police on Friday detained Kim, who has been accused of leading efforts to block Yoon’s detention.

Parliament

The National Assembly passed a revised bill proposed by the main opposition party on launching a special counsel probe into Yoon, Yonhap News reported on Saturday.

The bill was approved in a 188-86 vote during a parliamentary plenary session Friday, with ruling People Power Party lawmakers voting against it en masse. The opposition bloc led by the Democratic Party (DP) currently dominates the 300-member house with 192 seats.

The opposition decided to unilaterally table the revised bill after DP floor leader Park Chan-dae and his PPP counterpart, Kweon Seong-dong, failed to reach a compromise in talks presided over by National Assembly Speaker Woo Won-shik.

The opposition-proposed bill excludes allegations that Yoon committed "treason" by attempting to deliberately provoke war with North Korea from the original proposed by the DP and five other parties.