The International Skating Union says competitions at February's Olympics were marred by biased judging in favour of China, the next Winter Olympic host nation.

An ISU investigation found Chinese judges Chen Weiguang and Huang Feng guilty of boosting Chinese skaters' marks.

The ISU says Huang also dragged down the marks of German pair Aliona Savchenko and Bruno Massot, who won gold ahead of China's Sui Wenjing and Han Cong in second.

The Canadian duo of Meagan Duhamel and Eric Radford captured bronze in the event and announced their retirement from competitive figure skating in April.

Even with Chen's alleged manipulation of marks, Chinese skater Jin Boyang missed the medals in the men's competition, finishing fourth.

The ISU says the judges "committed one of the most serious ethical offences a judge can be accused of." Huang was banned for a year, while Chen is suspended for two years and banned from judging the 2022 Olympics in Beijing.