Tony Martin is giving up what he says is the "biggest trophy" of his career to raise money for children affected by the war in Ukraine.

The German, who retired at the end of last season, will auction off the silver medal he won in the time trial at the 2012 London Olympics.

The medal will be sold for the highest price and the money raised will be donated to RTL's "We help children" campaign and relief efforts in Ukraine.

"Every day I see terrible pictures from Ukraine on TV and feel so wrong to sit on the couch and accept this situation," Martin wrote on Instagram (opens in new tab).

"My deepest respect to all those who support those who need the most protection: the Ukrainian children and their families. I want to help in my own small way. That's why I decided to donate my silver medal from the London 2012 Olympics to RTL - Wir helfen Kindern (We Help Children)."

"It's not an easy thing to pull me away from the biggest trophy I could win in my career, but given the fact that millions of people have lost almost everything, it's something I really want to do."

The auction will be held on United Charities' website (opens in new tab) and will run through April 9. As of noon on Sunday as of this writing, the highest bid was 6,400 euros.Martin, a four-time time trial world champion, won a silver medal at the 2012 London Olympics, where Bradley Wiggins won gold.

The medal is described as being in "very good condition" with only the original box showing signs of "age".

"I sincerely hope that the people of Ukraine will soon regain peace and freedom," Martin said.

Martin is not the only cyclist trying to help the situation in Ukraine under Russian aggression in any way possible. Lachlan Morton rode 1,000 km from Germany to the Polish-Ukrainian border in 42 hours to raise awareness of how close the war is to Western Europe, raising more than $200,000 in the process.

Former professional Yaroslav Popovic was even more directly involved, helping to transport supplies to the Ukrainian border.

In recent weeks, various race winners, including Wout Van Art and Fabio Jacobsen, have helped draw attention to the horrors of war and the humanitarian crisis currently taking place.