Mark Cuban speculated Tuesday about the scope of Donald Trump's wealth, after the Federal Election Commission released a dismal campaign-finance report from the presumptive Republican nominee.

"If @realDonaldTrump were fractionally as rich as he says he is, he would write a $200 [million] check to propel his campaign," Cuban posted. "He doesn't have the cash."

The release of the Trump campaign's May FEC report showed the presumptive GOP nominee raised just about $3 million in his first month since sealing up the Republican nomination. Trump had roughly $1.3 million in cash on hand at the end of the month.

By comparison, presumptive Democratic nominee Hillary Clinton, who had yet to clinch her party's nomination, raised $28 million in May through the campaign and its "victory fund," finishing the month with $42.5 million on hand.

Cuban, who has flirted with the idea of serving as either Trump's or Clinton's running mate, has trolled Trump over his perceived wealth recently.

The billionaire business mogul, star of ABC's Shark Tank and owner of the NBA's Dallas Mavericks. said earlier this month that "it's not even close" as to who has more in liquid assets between the two. He also questioned whether Trump was a billionaire.

This story first appeared on Business Insider.