SEOUL - South Korea's former impeached president Yoon Suk-yeol on Saturday appeared before a special counsel team to undergo questioning as a suspect for corruption charges involving his wife Kim Keon-hee.

Yoon, who has been held at a detention center, arrived in a convoy vehicle at about 9:30 am local time (0030 GMT) at the office in Seoul of special counsel Min Joong-ki leading an investigation into corruption allegations involving the former presidential couple.

It marked the first questioning of Yoon for the corruption charges since the independent counsel team's investigation that was launched on July 2 and was scheduled to end on Dec 28.

The ruling on Yoon's wife was set to be delivered on Jan 28. The special counsel sought a 15-year prison term for Kim, who has been held at a detention center since August.

Yoon was named as an accomplice in charges involving his wife, who received free opinion polls worth 270 million won ($182,310) and a painting worth 140 million won as bribes.

He also faced charges of disclosing false information about his wife during the public debate as a presidential candidate in late 2021.

Yoon was expected to be questioned about whether he was involved in charges against his wife, who received expensive gifts in exchange for influence peddling in personnel matters and business favors.

The constitutional court upheld a motion to impeach Yoon on April 4 over his botched martial law bid last December, officially removing him from office.

READ MORE: South Korea begins new trial of ousted president Yoon over failed martial law

The ousted leader was indicted under detention on Jan 26 as a suspected ringleader of insurrection.