Police raided the residence of Gyeonggi Province Governor Lee Jae-myung on Friday as part of a probe into his alleged violations of election law during the June general elections.
The Bundang Police Station sent investigators to Lee's residence as well as four offices at Seongnam City Hall to search for and confiscate evidence. Lee served as Seongnam mayor before he won the Gyeonggi governorship in June.
He is accused of lying while appearing on a television debate during the election period by denying that he used his authority to institutionalize his older brother at a mental hospital.
Police launched the investigation after the minor opposition Bareunmirae Party filed a complaint against Lee last month.