MARK CUBAN: Maybe Donald Trump isn't releasing his tax returns because Hillary Clinton 'made more' money

Brash billionaire Mark Cuban took a swing at Donald Trump on Twitter Tuesday, suggesting that the reason he isn't releasing his tax returns is because Hillary and Bill Clinton "made more" money than him.

"Lots of people concerned how much money the Clinton's have made," he tweeted. "More interesting to me they have paid 43mm IN TAXES since 2007"

"I'd bet the 43mm in TAXES the Clinton's paid is not only more taxes than @realDonaldTrump has paid," he continued. "I'd bet they made more too."

Trump has raised eyebrows by repeatedly refusing to release his tax returns, citing an IRS audit that may or may not be completed ahead of the election. Every major party presidential candidate since 1976 has released their tax returns.

"It's not a tough argument looking at their taxes and fec filings that the Clinton's are much smarter business people and negotiators," the owner of the NBA's Dallas Mavericks and star of ABC's "Shark Tank" wrote, adding, "I get offers almost daily (at same $ as clintons) to give speeches Organizations want knowledge and insight. It's a great business."

"Maybe @realDonaldTrump didn't release his taxes become @HillaryClinton paid more in taxes than @realDonaldTrump made in income?" he continued.

Cuban was earlier excited about the prospects of a Trump presidency, but has recently soured to the point of frequently ridiculing the Manhattan billionaire. He has expressed interest in serving as either Trump's or Clinton's running mate earlier in the cycle.