This December 2021 file photo shows then Democratic Party presidential candidate Lee Jae-myung bowing deeply in an apology over allegations involving his son. (Yonhap)

Police have reopened an investigation into sex trafficking allegations against the eldest son of opposition leader Lee Jae-myung at the request of the prosecution, following their earlier decision to clear him of the charges, police officials said Tuesday.

The reinvestigation into Lee's 31-year-old son, Dong-ho, has been under way at the Gyeonggi Nambu Provincial Police Agency in Suwon, 50 kilometers south of Seoul, though the same police agency acquitted him of the prostitution charges three months ago, the officials said.