A district court has convicted Seoul's chief educator of running a smear campaign during last year's election, with the superintendent now facing a possible nullification of his election. 

The Seoul Central District Court Wednesday fined Cho Hee-yeon, superintendent of the Seoul Metropolitan Office of Education, 5 million won ($4,600), convicting him of spreading false rumors against his conservative rival Koh Seung-duk during the election campaign.

If the Supreme Court confirms the ruling, the liberal candidate will lose his job and have to return some 3 billion won in campaign funds.

Cho falsely accused Koh of using his U.S. green card to educate his two children in the United States, a judge said.

He organized press conferences and said in radio interviews that Koh would not be qualified to lead an education system in South Korea if the allegations were true.

Koh has denied being a U.S. permanent resident and said his children are U.S. citizens by birth.

The court said Cho continued to slander Koh even after the explanation and did so knowing it would help sway voters to choose him. (Yonhap)