SEOUL - South Korea's ruling party on Friday lost its overall majority in parliament after a second lawmaker-elect quit the party over scandal allegations.
Moon Dae-Sung, an International Olympic Committee (IOC) member, left the New Frontier Party (NFP) after a Seoul university confirmed he copied from someone else's paper for his 2007 doctoral thesis.
"I decided to accept the party's request to leave the NFP," Moon, 36, said in a statement. "I am sorry for causing concern to the people," he said.
"I hold myself responsible for all the controversy over the suspected plagiarism and confusion."
Moon has denied the plagiarism claims.
The conservative NFP this month won its second successive general election, securing 152 of the 300 National Assembly seats in the April 11 vote. It now has 150 seats.
On Wednesday lawmaker-elect Kim Hyung-Tae, 60, quit the ruling party after allegations of attempted rape 10 years ago which he denies.
The NFP has said it will try to sign up legislators elected as independents to restore its majority in parliament.
Moon, a professor at a Busan university, rose to fame after winning a taekwondo gold in the 2004 Athens Olympics.