The Supreme Court on Tuesday upheld a lower court ruling that convicted Seoul's chief educator of running a smear campaign during the 2014 election, however suspended his sentence, allowing him to retain his job.

In the decision, the court's First Petty Bench rejected an appeal from prosecutors and the defendant, Cho Hee-yeon, superintendent of the Seoul Metropolitan Office of Education. The Seoul High Court in September 2015 overturned a district court ruling that fined Cho 5 million won ($4,600) for spreading false rumors about his rival, Koh Seung-duk, during the election campaign.

The previous sentence reached in April of the same year could have nullified the election if confirmed by the Supreme Court.

In Tuesday's ruling, the top court agreed with the lower court's ruling that ordered Cho to pay a fine of 2.5 million won, suspended for two years, for his public comments against Koh, which the court deemed were not malicious and did not affect the results of the election.

During the 2014 campaign, Cho falsely accused Koh of using his US green card to educate his two children in the United States, after announcing at a press conferences on May 25, 2014, that he was tipped off about Koh's alleged acquisition of US citizenship.

It was seen as a move to stress that Koh was not qualified to lead the education system in South Korea if the allegations were true.

Koh denied being a US permanent resident and said his children are US citizens by birth. (Yonhap)