Reigning world figure skating champion Kim Yu-na will leave off her trademark "crown" earrings at the Sochi 2014 Winter Olympics in Russia.
The earrings by J.Estina, the jewelry brand of watchmaker Romanson, became an instant hit when Kim donned them during the 2010 Winter Olympics in Vancouver.
The reason is International Olympic Committee regulations, which ban athletes from promoting products by anyone other than the official sponsors.
After Kim's last Olympic win, some Japanese people demanded Kim should be stripped of the gold because she models for the brand.
Mao Asada of Japan was embroiled in a similar controversy because she used tissues by one of her sponsors in the ice rink.
J.Estina said the IOC decided Kim was not trying to promote the jewelry at the time. But while that may be true, she has still given the brand a huge boost by wearing it, with sales tripling on the day of the ladies' short program.
J.Estina CEO Kim Ki-moon said, "The three kinds of earrings that Kim wore in the short, free, and gala programs sold like hot cakes."
In Sochi the rules will be more strictly applied. "We were told that Kim will not be allowed to promote anything from Jan. 30 to Feb. 30," said J.Estina.
The IOC has strictly prohibited any advertising by athletes other than the official Olympic partners since the London games in 2012.
This has put Samsung, the official Olympic telecommunications partner, in a difficult situation. The company wanted to promote its ultra high definition TVs in addition to smartphones, but that is impossible because rival Panasonic is the official TV partner.
To become an official Olympic sponsor, companies pay an average of US$100 million, giving rise to criticism that the games are becoming too commercialized. Kim Ki-moon said, "For a small or medium-sized company like us, becoming an official Olympic partner is pie in the sky."