Prosecutors summoned the former chief of the Seoul Central District Prosecutors’ Office for questioning on Friday as part of an investigation into the justice ministry's inspection of then-Prosecutor General Yoon Suk Yeol in 2020 under the previous administration.

The office summoned Lee Sung-yoon, currently a researcher at the Institute of Justice, to grill him as a suspect on accusations of involvement in the transfer of key evidence from another case to the justice ministry's inspection committee to be used in an internal case against Yoon.

The investigation is looking into claims that the justice ministry under then-minister Choo Mi-ae carried out an internal inspection of Yoon with the intent to dismiss him as chief prosecutor.

Following the inspection, Yoon was suspended from duty for two months in late 2020 for a number of alleged wrongdoings, including impeding an investigation and violating political neutrality as a prosecutor.

Friday's questioning is expected to focus on whether Lee approved the transfer of evidence or exercised undue influence in the process.