Mitt Romney Warns of Possible 'Bombshell' in Trump's Taxes

Mitt Romney on Wednesday raised questions about Donald Trump's taxes that strikingly resembled attacks used against the former GOP presidential nominee four years ago.

"Frankly, I think we have a good reason to believe that there's a bombshell in Donald Trump's taxes," Romney said in an interview on Fox News.

More from NBC News:
Gloves off: Rubio takes first swings at Trump
240K without power after storm hits Northeast
Cracks in GOP opposition to Trump emerge

"I think there's something there. Either he's not anywhere near as wealthy as he says he is or he hasn't been paying the kind of taxes we would expect him to pay, or perhaps he hasn't been giving money to the vets or to the disabled like he's been telling us he's doing," he added.

Romney, who made hundreds of millions during a career in private equity, faced criticism during his failed presidential run for not releasing tax documents before 2010. In the midst of the general election, then-Senate Majority Leader Harry Reid made the false claim that Romney had not paid taxes for ten years.

Trump took to Twitter to respond to Romney, who he endorsed in 2012.

In the interview Romney also called on Marco Rubio and Ted Cruz to release "a couple years" of their back taxes.

"The voters have a right to see those tax returns before they decide who the nominee ought to be," Romney said.