Kim Yu-na Photo: CFP

 South Korea's Olympic body said Friday it would file a complaint with the international governing body for figure skating over controversial judging, which saw Olympic defending champion Kim Yu-na relegated to silver at the Winter Games.

The Korean Olympic Committee (KOC) said it would send a joint letter with the Korea Skating Union (KSU) to the International Skating Union (ISU) calling for an investigation into the composition of judges.

The committee said it would ask the ISU's disciplinary committee to see if there was a violation of ethical rules by the judging panel.

Kim, 23, finished second in Sochi behind Russian skater Adelina Sotnikova, despite turning in a characteristically error-free performance.

Her unexpected defeat sparked fury in South Korea where she is known as "Queen Yu-na" and enjoys a passionate, devoted following among millions of people of all ages.

She has repeatedly said she has put the Olympics behind her, but more than 2 million fans who believe Kim was robbed of a repeat Olympic gold medal have signed a petition calling for a review of the result.

Under growing pressure from fans, the KOC decided to take action, citing "unreasonable and unfair" judging.