'Maybe he isn't as rich as he claims': Clinton needles Trump for refusal to release taxes

Hillary Clinton on Tuesday challenged Donald Trump to release his taxes, seemingly attempting to taunt him into doing so by openly questioning if he is "as rich as he claims."

"You have to ask yourself, what's he afraid of?" Clinton asked an Ohio crowd during a lengthy speech on the economy.

The presumptive Democratic nominee noted that it was unprecedented in modern political history for a presidential candidate to refuse to release his or her taxes.

"Maybe he isn't as rich as he claims," she wondered.

Trump has said that he is under audit by the IRS and maintained throughout the 2016 cycle that it would be unwise to release his tax documents until the audit is complete.

His critics, however, have continued to hit him on the topic.

Throughout the primary season, Trump's rivals seized on the issue. In May, 2012 GOP nominee Mitt Romney speculated that there could be a "bombshell of unusual size" in the returns and said "it is disqualifying for a modern-day presidential nominee to refuse" to release them.

Clinton's question of Trump's fortune came just hours after billionaire investor Mark Cuban also expressed doubt that the real-estate mogul is as wealthy as he claims.