Former GOP presidential contender Mitt Romney called in to Fox host Neil Cavuto‘s show Wednesday afternoon, and speculated that Donald Trump might be deliberately concealing information about his net worth and donation habits from the American voters.

Watch the latest video at video.foxnews.com

Trump, Romney noted, had done a fine job harnessing people’s anger with a “political class that’s been fiddling and diddling,” leading to gridlock and inaction in Washington, but speculated that there were some as yet unearthed facts from the mogul’s past that could come back to haunt him — specifically, he said, he believed that “there’s a bombshell in Donad Trump’s taxes.”

I think there is something there. Either he is 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 the disable like he has been telling us he’s been doing. The reason I think there is a bombshell in there is because every time he is asked about his taxes he dodges and delays and says well we’re working on it.

The release of Romney’s own tax returns were a contentious issue in 2012, he noted, and but it was important to be transparent so voters could make an informed decision.

He continued:

He likes to tell people how well he’s done, why isn’t he willing to let us look at the tax return? It was an issue in my campaign. That’s why I’m so sensitive to it. We’re going to select our nominee – we really ought to see from all three of these fellows what their taxes look like to see if there is an issue there. I think in Donald Trump’s case it is likely to be a bombshell. […] There are things that could be issues and when people decide they don’t want to give you their taxes it’s usually because there’s something they don’t want you to see.

Trump responded on Twitter in characteristic fashion:

Mitt Romney,who totally blew an election that should have been won and whose tax returns made him look like a fool, is now playing tough guy — Donald J. Trump (@realDonaldTrump) February 24, 2016

When Mitt Romney asked me for my endorsement last time around, he was so awkward and goofy that we all should have known he could not win! — Donald J. Trump (@realDonaldTrump) February 24, 2016

Check out the video above, via Fox News.

[Image via screengrab]

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