Prosecutors on Thursday called in for questioning a former judge at the heart of mounting power abuse allegations involving the Supreme Court and its former chief justice.

Lim Jong-hun, former deputy head of the National Court Administration, the top court's governing body, was summoned for an interrogation at 9:30 a.m. next Monday, the Seoul Central District Prosecutors' Office said.

Lim, 59, is accused of playing a key role in illicit lobbying and trial manipulation used to achieve former Supreme Court Chief Justice Yang Sung-tae's pet project to establish a separate court of appeals. Lim worked for the NCA from 2012-2017.

The NCA, under Yang's direction, allegedly devised plans to influence rulings of politically sensitive trials to the advantage of then-President Park Geun-hye in exchange for her approval for setting up the appeals court.

Among the trials in question are the long-pending compensation case for Korean victims of Japan's wartime forced labor and a case that involves a progressive teachers' union.

Lim is suspected of being the key man who was in charge of carrying out Yang's schemes.

The top court has been under fire over the allegations, with rising calls for summoning Yang. (Yonhap)