People around President Donald Trump think that if the Russia investigation touches the president's finances, it could take him down, the author of an explosive tell-all book told CNBC on Tuesday.

Michael Wolff, author of "Fire and Fury: Inside the Trump White House," said administration officials and Trump confidantes he spoke to do not think the president colluded with Moscow to win the 2016 election. However, they think if special counsel Robert Mueller looks into Trump's finances, it could be perilous for the president, Wolff claimed.

"People don't think in the White House — don't think that he colluded with Russia. … They do think that if the investigation goes near his finances, he's sunk. Everybody, again, to a man," Wolff said in a "Squawk Box" interview.



The president has repeatedly denied any cooperation with Moscow as an investigation into Russian efforts to influence the 2016 election continues. Last year, Trump told The New York Times that a Mueller probe of his finances as part of the investigation would cross a red line.