Ann Romney said in an interview set to air Thursday that "there's nothing we're hiding" in regards to her and husband Mitt Romney's personal finances, and insisted again the campaign had no plans to release additional tax return details.

"We have been very transparent to what's legally required of us,” Romney said in an interview with NBC News. “There's going to be no more tax releases given."

Romney echoed previous comments by her husband, saying that releasing more tax information "will only give [the opposition] more ammunition."

The first lady hopeful also emphasized that the couple's finances had been held in a blind trust since Romney was elected governor of Massachusetts in 2002, looking to downplay Democratic swipes at the offshore holdings and foreign bank account revealed in a first round of disclosures.

"It's been managed by a blind trust since before Mitt was governor, you know, 2002 forward,” Romney said. “And so, you know, I'll be curious to see what's in there, too." 

Mitt Romney's taxes have come under new scrutiny after Senate Majority Leader Harry Reid's (D-Nev.) charges on the floor of the Senate that an anonymous source had told him the Romneys had avoided paying federal income taxes for a decade.

On Tuesday, Sen. John McCain (R-Ariz.) said he was "absolutely confident" that was untrue, based on the 20-plus years' worth of disclosures turned over during his 2008 vice presidential vetting of the former governor.

"Nothing in his tax returns showed that he did not pay taxes," McCain said during an interview with the Las Vegas Sun.