The special counsel investigating corruption allegations against former first lady Kim Keon-hee has summoned People Power Party lawmaker Yoon Sang-hyun over suspicions that former President Yoon Suk Yeol and Kim interfered in the party's candidate nominations during past elections.

Yoon appeared at special counsel Min Joong-ki's office in central Seoul at around 9:25 a.m. on Sunday.

Before entering for questioning, Yoon told reporters he would cooperate with the investigation sincerely and truthfully.

Yoon, along with the former presidential couple, is suspected of meddling in the party's nomination process during the 2022 local and by-elections while serving as chair of the party's nomination committee.

The former president and his wife allegedly accepted free polling services from self-proclaimed power broker Myung Tae-kyun during the 2022 presidential campaign and, in return, exerted undue influence to secure a by-election nomination for former lawmaker Kim Young-sun.