A question of sport for the pub quizzers: Which prominent sports figure likely to be the next President of his country failed a pre-Olympics drugs test?

The answer? Vitali Klitschko, until this week the world heavyweight champion and now presently engaged in the toughest fight of his life as leader of a political party his native Ukraine aiming to KO the dictatorial reigning incumbent.

Klitschko has proved himself one of boxing's supreme champions, yet how many recall that back in 1996 he was ruled out of representing Ukraine in the Atlanta Games after testing positive for a steroid derivative which he claimed he had taken unwittingly when trying to recover from injury?

Instead his place at super-heavyweight was taken by his younger brother Wladimir, who won the gold medal, and subsequently both went on to dominate the professional heavyweight division, tidying up the fragmented titles between them.

Vitali's World Boxing Council (WBC) belt has always been regarded as the most authentic, but yesterday that was relinquished after almost a decade in order for him to concentrate on the political and ideological struggle in Ukraine.

Vitali Klitschko has dominated the world heavyweight scene, losing only two fights in his professional career ©Bongarts/Getty Images

The 6ft 7in "Dr Ironfist" is currently standing tall on the streets of capital Kyiv, attempting to calm the violent anti-Government protests that have captured the world's attention

The WBC have declared him "Champion Emeritus" in recognition of his magnificent contribution to the sport.

Technically this allows him to challenge a new champion should he wish to resume boxing. But the 42-year-old Klitschko says:"That is something I currently cannot imagine. My focus is on politics in Ukraine and I feel the people there need me."

Apart from Muhammad Ali, Klitschko surely is the most remarkable heavyweight champion in history. Like Wladimir, 37,he holds a PhD in sports science and is as fluent in four languages as he has been with those iron fists.

Now he has an altogether different fight on his hands as leader of pro-Western, anti-Russian party the Ukrainian Democratic Alliance for Reform, whose initials appropriately translate into the Ukrainian word for Punch.

Massive crowds have demonstrated for weeks in Kyiv against vilified President Viktor Yanukovych's decision to shun closer ties with the European Union and Klitschko has been prominent in the protests which have infuriated Russia's president Vladimir Putin, who is known to be pressuring the Ukrainian Government.

World heavyweight boxing champion Vitali Klitschko has joined demonstrators on the streets in Ukraine's capital Kyiv as protests against the Government have continued ©AFP/Getty Images

Klitschko's anti-corruption, pro-European platform has made him Ukraine's most popular politician. He is now said to be 20 per cent ahead in the polls for a Presidential race likely to be far fiercer than any of his 17 title fights, emerging as the main challenger to Yanukovich in elections scheduled for 2015.

His last fight in the ring was in September 2012 when he stopped Manuel Charr in the fourth round. Prior to that was his points defeat of Britain's Dereck Chisora, who notoriously spat water in his face at the weigh-in. Klitschko's stoic reaction was an indication of the character he now displays as a political leader.

He retires boasting the highest knockout percentage in history, more than 87 per cent of his opponents being chopped down with that wrecking ball right hand.

Klitschko himself has never been knocked off his feet in 47 bouts and he has barely lost a round since his 2003 defeat in an epic battle with Lennox Lewis when he was halted with an hideaous eye injury when ahead on points.

That was one of only two defeats, the other when he was forced to retire with a shoulder injury against Chris Byrd.

Now the WBC are likely to match leading contender Bermane Stiverne, a Haitian-born Canadian, with America's big-punching sensation Deontay Wilder for the vacant title.

However another possible scenario might see the title might remain in the Klitschko family, with Stiverne or Wilder paired with Wladimir, who holds the other three versions- WBA, IBF and WBO.

This would bring about a unified world heavyweight title for the first time since Lewis retired after fighting Vitali ten years ago.

Crowd of protesters gathered in Kyiv's Independence Square watch Vitali Klitschko, now Ukraine's opposition leader, delivering a speech ©Getty Images

As for Vitali, this son of a former Soviet air force colonel now becomes a true political heavyweight, believing his sports career will assist him to triumph. " Success in any sport requires concentration, training, determination and talent," he says. "Sport gave me the will to win, the ability to make quick decisions, to realise their full potential. These qualities are very important in politics.

"My country needs a change. Ukrainians deserve a better life . I saw how people live in Europe and the US and came to politics to introduce standards of living, values, rights, and freedoms of the European community in my country.

"My main goal is for Ukraine to be a European, modern country with European standards of life. I will decide with people who have the same vision, the same dream to change the situation."

Klitschko is following a similar political path to another contemporary boxing legend, Manny Pacquiao, now a Congressman in the Philippines, who is also considering a run for the Presidency there.

Fighting out of the pro-Western "Orange" corner against the pro-Moscow "Red" corner Klitschko has had a long-standing interest in politics, previously running for mayor of Kyiv and being an elected a member of the Ukraine Parliament - where fellow national sports icon Sergeyi Bubka was also a member from 2002 until 2006 before electing to concentrate on sports politics.

Vitali Klitschko addresses the Ukraine Parliament in Kyiv where he claims he is fighting with his mind, not his fists ©AFP/Getty Images

On several occasions he has acted as peacemaker in the regular punch-ups in the volatile Parliament. He explains: "In the ring they call me Dr Ironfist. Perhaps some expected me to begin my Parliamentary career by bashing heads, literally. However, I said early on that my style in politics will be focused on the battle for ideas that lead to changes in Ukraine."

K1, as he is known, has represented Ukraine at the Council of Europe and, first made his first mark in politics in the ring in December 2004, when he wore an orange flag on his shorts in support of the revolution that initially ousted President Yanukovych after he was accused of election fraud.

"These days I spend 90 per cent of my time on politics," he told insidethegames last year at his Alpine training camp in Austria. "Sometimes I don't sleep too well because the brain is burning with what I have to do.

"In boxing, I am alone in the ring but in politics it is team work. I have some good people around me. Alone I can do nothing.

"Ukraine needs to be a European country, we are European with our history and mentality. Geographically we are in the middle of Europe but we are very far away from Europe with our life standards.

"We need to make many changes. In 1991, I was 20 years old. I voted for the independence of our country. Everyone had a dream to build a new modern democratic Ukraine. Last summer we celebrated 20 years independence. Sadly, we have become a corrupt country. Now I want to stop my homeland sliding into tyranny."

Vitali Klitschko has made no secret of his political affiliations, wearing an orange flag on his trunks in December 2004, when he beat Britain's Danny Williams in Las Vegas ©Getty Images

As an MP, he has campaigned vigorously for the release of Mrs Yulia Tymoshenko, the former Ukrainian Prime Minister was imprisoned for "abuse of office" - a charge that her supporters claim was politically motivated

"Democracy is my dream and and that is what I am fighting for. But we cannot be a democratic country with political prisoners."

Klitschko's ideals surely would have found favour with the late Nelson Mandela, who said he not fought for democracy in South Africa he would love to have been the world heavyweight champion.

How apt that one who actually is now treads a similar long walk to freedom

That drugs aberration long forgotten and forgiven, the great champion has become a contender again, this time in an altogether dirtier arena.

Mandela surely would have applauded this fellow freedom fighter.

Alan Hubbard is a sports columnist for the The Independent on Sunday, and a former sports editor of The Observer. He has covered a total of 16 Summer and Winter Games, 10 Commonwealth Games