Rep. Lee Choon-suak of the ruling Democratic Party quit the party on Tuesday over allegations that he traded stocks under someone else’s name.

Earlier in the day, a local media outlet released photos that appeared to show Lee trading stocks on a mobile phone using the name of one of his aides at the parliamentary plenary chamber the previous day. 

Party spokesperson Kwon Hyang-yup said in a press notice on Tuesday that the four-term lawmaker conveyed his decision to step aside in a phone call with party Chairman Jung Chung-rae around 8 p.m., saying he was sorry for causing harm to the party. 

Jung reportedly said he was deeply sorry for causing public concern over such an unfortunate matter and that as the party leader, he bore a heavy sense of responsibility. 

Lee’s departure comes just six hours after Jung ordered the party’s ethics inspection team to launch an investigation into the case.