'Owned by the Russian mob': Trump biographer explains how the president's first 'fixer' Roy Cohn set him up with the mafia

Though Donald Trump has consistently claimed that he has no business interests in Russia, the author of a new book alleging the president was tied to Russia mobsters laundering money in his properties put that claim to the test during an MSNBC interview Friday.

As writer Craig Unger told MSNBC's Chris Matthews, the connection between Trump and the Russian mob was forged by the president's old lawyer, the late Roy Cohn.

"[Cohn] was also a lawyer for the Italian mafia, for the Gambino and Genovese families, and in the 80's they began partnering with the Russians," Unger said.

With the fall of the Soviet Union, Russians began making so much money that "they needed to launder it," the writer continued. In 1984, David Bogatin, a Russian national with ties to the mob, paid Trump $6 million in cash for five condos — the equivalent of about $15 million by modern standards.

"According to the state attorney general of New York," Unger noted, "that was money laundering."

After clarifying to Matthews how and why the capital began flowing from the former USSR to the United States, the writer pointed out that "the best way to launder money is real estate."

"There are almost no regulations in real estate," Unger said, "in terms of [how] you can buy it anonymously, through shell companies, pay all-cash transactions — bam, when you sell it, it's laundered."

The writer noted that although he doesn't have records for the alleged cash transactions between Trump and the Russian mob, those documents may soon come to light.

"I can't penetrate all the shell companies, and this is one of the interesting things today with [former Trump Organization CFO] Allen Weisselberg flipping," Unger said. "Obviously I don't have subpoena power, but I think you're going to find that those records are going to be opened by the prosecutors now."

Watch below, via MSNBC: