Donald Trump claims he can't release his tax returns until he's done being audited by the IRS. But the federal agency on Friday said that's not true.

"Federal privacy rules prohibit the IRS from discussing individual tax matters. Nothing prevents individuals from sharing their own tax information," a spokesperson for the IRS said in a statement.

The Republican presidential front-runner's refusal to release his tax documents came up repeatedly during Thursday's GOP debate, hours after former Republican nominee Mitt Romney suggested that Trump's reluctance stems from the possibility there might be a "bombshell" in his taxes.

"I want to [release them], except for many years, I've been audited every year," Trump said during the debate. "Twelve years, or something like that. Every year they audit me, audit me, audit me. Nobody gets audited — I have friends that are very wealthy people. They never get audited. I get audited every year. I will absolutely give my return, but I'm being audited now for two or three years, so I can't do it until the audit is finished, obviously. And I think people would understand that."

While the IRS claims nothing is preventing the billionaire from releasing the information, Steven Golburd, an attorney specializing in tax law, told the Washington Post Friday it may indeed be in Trump's best interest to keep them private.

"Think of an audit as an investigation, an on-going investigation," Goldburd said. "Any person that has legal counsel, their legal counsel will say, 'If you're under investigation, you should not be talking to the media, you should not be talking to anyone other than your legal counsel or through your legal counsel.'"

Trump doubled down on his refusal to release his returns during a campaign rally Friday in Fort Worth, Texas. The billionaire told the crowd that Romney didn't release his tax returns until Sept. 21, 2012 — less than two months before voters cast their ballots in the 2012 presidential election.