WASHINGTON,USA (AFP) — In a country riven by taxation discord, Republican White House hopeful Mitt Romney has hit on a populist measure that is a sure-fire winner: tax relief for US Olympians on the medals they win.

Some Republicans, including possible Romney running-mate Senator Marco Rubio, had already spoken out against the little-noticed element in the tax code that taxes athletes for bringing home gold, silver or bronze.

Yesterday a senior Romney adviser said the presumptive Republican nominee challenging President Barack Obama for the White House in November was also against the policy.

Romney headed the 2002 Winter Games in Salt Lake City, and "he believes that there should be no taxation of the type that you're describing," advisor Eric Fehrnstrom told reporters.

Romney is a multimillionaire former businessman and investor, and advocates significant tax cuts for individuals and corporations and simplification of the tax code.

The comments come a day after Rubio introduced the Olympic Tax Elimination Act in the Senate. Republicans and Democrats reportedly introduced similar legislation in the House.

"Our tax code is a complicated and burdensome mess that too often punishes success, and the tax imposed on Olympic medal winners is a classic example of this madness," said Rubio.

"Athletes representing our nation overseas in the Olympics shouldn't have to worry about an extra tax bill waiting for them back home."

The legislation follows a report by the conservative group Americans for Tax Reform (ATR), which warned that athletes could be required to pay up to US$9,000 in taxes to the Internal Revenue Service for each gold medal.

That's not just for the medal itself; the US Olympic Organising Committee awards US$25,000 to gold medal winners, US$15,000 for silver and US$10,000 for bronze.

Fact-checker group PolitiFact rated the ATR report as "mostly false," arguing that most athletes are not huge earners like swimmer Michael Phelps and would not be subject to high tax rates, and that they could also deduct their training expenses, which often amount to several thousand dollars per year, from their income.

US lawmakers are currently locked in a fierce tax debate.

Republicans, including Romney, want tax cuts from the era of former president George W Bush extended for another year for everyone, while Obama and Democrats want the tax breaks extended only for families making under US$250,000, meaning wealthier Americans would see their taxes rise in 2013.