Eliza Collins

USA TODAY

Mitt Romney thinks the fact that Donald Trump won’t release his tax returns is “disqualifying” for the presidency.

In a Facebook post Wednesday, the 2012 Republican nominee called on Trump to release his tax returns. (The tweet he used to announce his post said “Mr. Trump, tear down that tax wall.”)

“It is disqualifying for a modern-day presidential nominee to refuse to release tax returns to the voters, especially one who has not been subject to public scrutiny in either military or public service. Tax returns provide the public with its sole confirmation of the veracity of a candidate's representations regarding charities, priorities, wealth, tax conformance, and conflicts of interest. Further, while not a likely circumstance, the potential for hidden inappropriate associations with foreign entities, criminal organizations, or other unsavory groups is simply too great a risk to ignore for someone who is seeking to become commander-in-chief.”

And about Trump’s claim he’s being audited? Romney said: “So?”

“There is nothing that prevents releasing tax returns that are being audited,” Romney wrote. “Given Mr. Trump's equanimity with other flaws in his history, we can only assume it's a bombshell of unusual size.”

Romney’s speculation about what is inside Trump’s returns follows an interview with the Associated Press Tuesday where the billionaire said he didn’t expect to release his returns before the election.

"There's nothing to learn from them," Trump said. He told the AP that he was being audited, so he couldn't release them — that's not exactly the case, though. He added that he also didn’t believe voters cared about the returns.

On Wednesday afternoon, Trump tweeted a clarification to the AP report.

Anthony Scaramucci — who recently joined Trump's national finance committee, The Washington Post reported — told Fox News Wednesday that there were three reasons Trump wasn't releasing his taxes: the complexity of the return, the audit and a desire to avoid a "nightmare situation with opposition research trying to pick holes through the return."

The “bombshell” charge is not new for Romney. In February he called on Texas Sen. Ted Cruz, Florida Sen. Marco Rubio and Trump to release their taxes (Romney released his in January 2012 after much pressure) and said that Trump could be holding off because of a "bombshell."

Romney has disavowed Trump as his party’s presumptive nominee and said he won’t attend the convention this summer.