Prosecutors again summoned former Supreme Court Chief Justice Yang Sung-tae for questioning on Monday over his alleged involvement in a power abuse scandal, as they plan to decide this week whether to request a warrant to detain him.

The team handling the case at the Seoul Central District Prosecutors’ Office began interrogating the 71-year-old former top court chief Monday morning, three days after they grilled him for over 14 hours. 

Prosecutors suspect that Yang sought to use politically sensitive cases as bargaining chips to win former President Park Geun-hye’s support for his plan to establish a court of appeals.

During the second interrogation session with Yang on Monday, prosecutors were to question him on whether he interfered in the trial of the now-defunct Unified Progressive Party, which was accused of treason and ultimately forced to disband; whether he ordered the illegal collection of classified information within the Constitutional Court; whether he sought to cover up alleged corruption on the part of a former Busan High Court judge; and whether he illegally used the operating budget for the office of the court spokesman.

The Constitutional Court disbanded the UPP in December 2014 at the request of the Justice Ministry. The Supreme Court sentenced UPP lawmaker Lee Seok-ki to nine years in prison in 2015 for treason and violating the National Security Law.

Prosecutors also suspect that under the instructions of Yang or the top brass of the National Court Administration, the NCA received reports on over 300 cases from a senior judge surnamed Choi at the Constitutional Court.

Yang was expected to deny most of the allegations.

Regarding his alleged involvement in a trial involving Korean victims of forced labor under colonial Japan, Yang said he couldn’t remember or that it was handled by the NCA’s working-level staff.

About the allegations that he blacklisted judges of liberal political orientation, Yang said the NCA exercised its lawful personnel management rights and that its actions did not constitute abuses of authority.

After his first interrogation at the prosecutors’ office on Friday, which ended at midnight, Yang spent three hours reading the record of his session with the prosecutors. On Saturday, he went back to the prosecutors’ office to go through the record with them.

By Kim So-hyun (sophie@heraldcorp.com)