Horuna plans to use the proceeds to buy a vehicle for a unit fighting against Russia in the ongoing war.

The item of clothing contains "a little blood of my opponents here, and it also has all the emotions I experienced in Tokyo", Horuna wrote.

A target price of UAH200,00 (£4,500/$5,400/€5,300) has been set.

The karateka won men's under-75 kilograms kumite bronze on Karate's Olympic debut at Tokyo 2020 last year.

Now 33, Horuna won a silver medal at this year's World Games and is also a European and European Games champion.

This is not the first time Horuna has sold a precious piece of memorabilia to raise funds in support of Ukraine's efforts to repel the Russian invasion.

Horuna previously sold the Olympic medal for $20,500 (£16,300/€19,400). 

A Japanese national won that auction and has since contacted Horuna to say they plan to return the bronze when the war is over.

The World Karate Federation (WKF) is among the global governing bodies to have banned competitors from Russia and Belarus outright because of the war in Ukraine.

The WKF also moved its season-ending Karate 1-Premier League leg from Moscow to Los Angeles.

At least 5,327 civilians have been killed in Ukraine since Russia launched a full-scale invasion on February 24, according to the Untied Nations, which fears the true figure is far higher.

In excess of 10 million refugees have fled the country and the combined military death toll is estimated to exceed 20,000.

Ukrainian President Volodymyr Zelenskyy has accused Russia of carrying out war crimes, including executing civilians.

Russia calls the attack a "special military operation" and claims to be seeking to "de-nazify" Ukraine - an assertion widely dismissed as fictitious.