US Republican party presidential hopeful Mitt Romney released data showing $42.6 million of income for 2010 and 2011, amid controversy about his wealth in relation to average US citizens, the Washington Post reported Tuesday. The candidate - who has come under attack for heading a private equity company that put thousands out of work while he got rich - will officially release the data Tuesday, but gave some US media outlets a preview late Monday. All the income listed was from capital gains, as well as stock dividends and interest payments. The information listed 7 million dollars in charitable donations over the last two years, the Post reported. The figures show that Romney and his wife paid about $3.2 million in federal taxes in 2011, in line with a tax rate of 15.4 percent. That rate — the prevailing rate for investment earnings — is significantly lower than that paid by most US citizens on their salaried income. A debate about economic inequality is framing many aspects of the race to pick a presidential candidate to lead the traditionally pro-business Republican Party into presidential elections in November. In a candidates' debate late Monday, Romney called his tax bill “entirely legal and fair,” the Post reported. “I'm proud of the fact that I pay a lot of taxes.” Romney had been considered the party's front-runner for the nomination until about a week ago. But his star declined as it emerged that a presumed victory in the Iowa caucuses had actually been a win for competitor Rick Santorum, and after Newt Gingrich came out on top in the South Carolina primaries. Republican Party members in three of the US' 50 states have so far made their picks for whom to nominate for the presidential election. Florida is set to choose next, on January 31. Romney's Republican opponents have questioned whether he had something to hide because he had refused, until this week, to release details about his income and taxes paid. US President Barack Obama has indicated he will make divisions in income an election year issue, with calls for higher taxes for high earners. The US presidential election is on November 6.