Donald Trump’s massive debts—he owes hundreds of millions of dollars—are the subject of continuous congressional and journalistic scrutiny. But for years, one Trump loan has been particularly mystifying: a debt of more than $50 million that Trump claims he owes to one of his own companies. According to tax and financial experts, the loan, which Trump has never fully explained, might be part of a controversial tax avoidance scheme known as debt parking. Yet a Mother Jones investigation has uncovered information that raises questions about the very existence of this loan, presenting the possibility that this debt was concocted as a ploy to evade income taxes—a move that could constitute tax fraud.

John Solomon had grand plans for the digital future of the Center for Public Integrity. But there was always a catch...