World heavyweight champion Vitali Klitschko has given up his WBC title and says he is unlikely to fight again because he is focusing on politics.
The World Boxing Council have made him a "champion emeritus", which would allow him to directly challenge a new champion if he wants to resume boxing.
But the 42-year-old, who is a Ukrainian opposition leader, said: "That is something I currently cannot imagine.
"My focus is on politics in Ukraine and I feel the people there need me."
Klitschko beat Herbie Hide to win the WBO world
heavyweight title in London in 1999
Massive crowds have demonstrated for weeks in Kiev against president Viktor Yanukovych's decision to shun closer ties with the European Union.
Klitschko has won 45 of his 47 professional fights, 41 by knockout, and his younger brother Wladimir holds the other significant world heavyweight belts.
"I thank the WBC and its president Jose Sulaiman for the support in our battle for democracy and freedom in Ukraine," added the older Klitschko.