Mitt Romney's presidential campaign has not yet clarified if the candidate has ever paid less than a 13.9 percent tax rate.
Romney has said he'll only release two years of tax returns, but he told ABC's David Muir over the weekend he didn't know offhand if he'd ever paid a rate lower than the 13.9 percent he paid in 2010. Romney suggested that he would look into it.
"I haven't calculated that," said Romney. "I'm happy to go back and look, but my view is I've paid all the taxes required by law."
As proof that he had paid all the taxes required by law, Romney said to Muir that he had been audited in the past.
The Romney campaign did not respond Monday to questions about when, specifically, the audit took place.
"The audit did not result in a fine or penalty. Mitt Romney has fully complied with U.S. law and he has paid 100 percent of what he has owed," said Ryan Williams, a campaign spokesman.
Brad Malt, the trustee who handles Romney's personal finances has said there was an audit that took place more than a decade ago.
"Governor Romney has not been audited by the IRS in the last 10 years," Malt said in January.
In a statement Monday, campaign spokeswoman Gail Gitcho did not say what tax rate Romney has paid in the past or whether he ever paid less than 13.9 percent of his income, but she did reiterate that he has paid all the taxes he legally had to pay.
"Mitt Romney has paid his taxes in full compliance with U.S. law, and he has paid 100 percent of what he has owed," she said in a statement to ABC News. "As has previously been reported, in 2011, the Romneys will pay more than $3.2 million in taxes on $20.9 million in mostly investment income and will have donated more than $4 million to charity. In 2010, The Romneys paid more than $3 million in taxes on $21.6 million in mostly investment income and donated nearly $3 million to charity."
Gitcho pointed out that the Romneys have released hundreds of pages of tax returns from 2010 and provided an estimate for what they paid in 2011. The final 2011 returns are expected when they are completed.