President Donald Trump's allies are becoming increasingly concerned about the prospect of Michael Cohen, a longtime attorney for Trump, turning on the president.

"If anyone can blow up Trump, it's him," a former White House official told Vanity Fair.

Cohen is the focus of a federal investigation into whether he violated campaign-finance laws or committed bank fraud. He has not been charged with a crime.

Allies and advisers of President Donald Trump are reportedly getting more and more worried about the prospect of Michael Cohen, Trump's longtime lawyer, making a deal with prosecutors to turn on Trump.

Many think Cohen's troubles are as threatening to Trump as the special counsel Robert Mueller's investigation into Russia's election meddling and whether the Trump campaign had a role in it.

"Trump should be super worried about Michael Cohen," a former White House official told Vanity Fair. "If anyone can blow up Trump, it's him."

Vanity Fair described a source close to Cohen as saying Cohen had told he friends he "expects to be arrested any day now." When asked for comment by the publication, Cohen denied that.

Cohen is the focus of a federal investigation in the Southern District of New York into whether he violated campaign-finance laws or committed bank fraud. Investigators are said to be interested in a $130,000 payment he made to the adult-film actress Stormy Daniels weeks before the 2016 election in exchange for her silence about her allegations of an affair with Trump years ago. Cohen has not been charged with a crime.