WASHINGTON (REUTERS/BLOOMBERG) - United States Republican presidential candidate Ted Cruz released four years of his and wife Heidi's tax returns on Saturday (Feb 27), ranging from 2011 to 2014, showing US$389,124 (S$547, 836) taxes paid on US$1.2 million in 2014.
Senator Cruz's filings follow a similar release of returns on Saturday by rival Marco Rubio, a US senator from Florida.
Both campaigns called on billionaire businessman and Republican front-runner Donald Trump to make his returns public, too.
Sen Cruz and his wife paid US$1.5 million in federal income taxes from 2011 through 2014 on adjusted gross income totaling more than US$5 million, according to partial tax returns released in e-mails to reporters by the Republican presidential candidate's campaign Saturday.
The couple's average federal tax rate over the four-year period was 29.9 per cent. But because the releases did not include schedules that would detail their sources of income or the deductions they claimed, the returns provide comparatively scant information.
Sen Rubio and his wife Jeanette reported US$2.3 million in income over the past five years and paid US$526,092 in federal income taxes, according to tax documents released by the presidential candidate's campaign on Saturday.
Sen Rubio's campaign released five years of documents - though it provided only partial returns, omitting the detailed schedules that would bring transparency into the couple's income, charitable giving and tax strategies.
"The gross numbers without the schedules don't tell you anything," said Mr Martin Shenkman, a tax lawyer and certified public accountant in Fort Lee, New Jersey.
Sen Rubio's campaign didn't respond immediately to a request for comment.
The records - which amount to the first two pages of each annual tax filing the Rubios made from 2010 through 2014 - show that they paid federal income taxes at the rate of about 23 per cent.
Coupled with prior returns from 2000 through 2009, which Sen Rubio released when he ran for the US Senate in Florida, the documents raise questions, Mr Shenkman said. "He's attacking Trump on the same disclosure issues, but his own disclosures are obfuscatory," Mr Shenkman said.
Sen Rubio released his tax information three days after 2012 Republican presidential nominee Mitt Romney called for the GOP candidates to show their tax information to voters.
Among the documents that weren't disclosed: Schedule C, which would have revealed how much of the Rubios' income resulted from business interests, and Schedule E, which would show their income from rental real estate, royalties, partnerships, S corporations and trusts.
The lack of detail is particularly pronounced for the tax year 2012, when the Rubios' adjusted gross income soared to US$929,439, almost four times the US$276,059 they reported the prior year, and more than five times 2010's amount, US$183,826.
Most of their 2012 income - US$711,243 - came from business interests, but without Schedule C, it's impossible to determine precisely what those interests were.
In addition, US$34,002 of the amount came from rental real estate, royalties, partnerships, S corporations and trusts - but without Schedule E, it's also impossible to know details.
In 2011, when the Rubios had adjusted gross income of US$276,059, they reported no Schedule C business income. Their Schedule E income, however, was nearly three times that of 2012 - US$101,652. In 2012, the couple paid federal taxes of US$254,694, an effective rate of 27.4 per cent, the highest rate they paid in the past five years.
The Rubio campaign said in a statement that accompanied the release that "the effective federal tax rate paid by the Rubio family in each of the past five years has been in line with rates paid by Americans of similar income levels".
Sen Rubio, Florida's junior senator, has portrayed himself as a success story who grew up the son of a bartender and hotel maid in a working-class household and worked his way to the US Senate.
He has said repeatedly that free enterprise allows opportunity for people on all parts of the economic spectrum. While Sen Rubio has attempted to position himself as an alternative Mr to Trump - scoring a series of shots at the GOP front-runner during the party's 10th debate in Houston on Thursday - he placed a distant second in Tuesday's Nevada caucuses, second in South Carolina, fifth in New Hampshire and third in Iowa.
In posting a link to Sen Rubio's taxes on Twitter, Sen Rubio's campaign communications director Alex Conant challenged Trump to do likewise.
While Sen Rubio's release makes him the first of the three leading GOP candidates to release at least some material, the depth of his documentation lags well behind that of Democratic frontrunner Hillary Clinton, who released full returns. In 2012, Romney released schedules and details with his taxes as well.
Sen Rubio, meanwhile, kept up his attacks on Mr Trump on Saturday. "There comes a time when you have to stand up," he said Saturday in Huntsville, Alabama. "I had to get a little medieval on him, and I did so because he's a con man."
Sen Cruz, 45, won the Iowa caucuses but has found himself grappling with Sen Rubio of Florida, for second place behind Mr Trump in subsequent contests.
Mr Trump said on Thursday that he is being audited and will not release his tax returns until the audit is over and could not guarantee he would release them in time for the general election.