The 312-page transcript, released by Sen. Dianne Feinstein, D-Calif., on Tuesday over the reported objections of Sen. Chuck Grassley, R-Iowa, documents nearly 10 hours of testimony that delves into Trump's purported wealth, the financial health of some of his properties, his business ties to disreputable figures and his public statements regarding his own finances.
Simpson said his intelligence-gathering firm did not have access to Trump's personal tax returns beyond what had already been leaked to the media. But the firm, Simpson said, did secure Trump's "tax bills," from which it concluded "that his statements about what individual properties were worth were greatly exaggerated."
That exaggeration extended to the Trump Organization's golf courses. Simpson said that his firm's review of public financial statements showed that "they were not profitable entities."
"I don't specifically recall. I just remember that these were not doing very well and that he'd sunk a lot of money into them and he hadn't gotten a lot of money back yet," Simpson said.
Simpson's allegations about Trump's business relationships, particularly with convicted felon Felix Sater, contradicted statements Trump had previously made under oath.
Trump "testified under oath he wouldn't know Felix if he ran into him in the street," Simpson said. "That was not true."
In a 2013 deposition, Trump had distanced himself from Sater, saying, "I don't know him well at all," and "if he were sitting in the room right now, I really wouldn't know what he looked like."
"He knew him well," Simpson said, "and, in fact, continued to associate with him long after he learned of Felix's organized crime ties."
Simpson's claim stunned some observers.
"It's an allegation of perjury," said Elizabeth McLaughlin, a retired lawyer and founder of the left-leaning Gaia Project for Women's Leadership. "It's eye-popping."
The White House did not respond to CNBC's request for comment.