David Tepper slams Donald Trump for being selfish, calls him 'father of lies'

David Tepper: Trump didn't give one dime!

Billionaire David Tepper slammed Donald Trump on Monday, saying he "masquerades as an angel of light, but he is the father of lies."

The hedge fund manager told CNBC's "Squawk Box" that he watched Trump's wife, Melania, introduce him as a generous, giving person in a campaign appearance over the weekend. Tepper disputed that, contending the Republican presidential candidate did not give money in the wake of some New York-area disasters.

"During Sandy, the big Sandy benefit, the big 9/11 benefit, not one dime. Not one dime! You can't tell me this is a charitable, generous person," the Appaloosa Management founder said, raising his voice to a scream.

"Trump masquerades as an angel of light, but he is the father of lies," Tepper asserted.

Trump has repeatedly boasted about his charitable giving on the campaign trail, even skipping a GOP primary debate to hold a fundraiser for veterans. But investigations, particularly from The Washington Post, have found Trump's real giving has not measured up to his talk.

In a subsequent interview on "Squawk Box," Trump campaign manager Kellyanne Conway said: "Mr. Trump has been very generous with his time and his money over a number of decades. … I've witnessed it first hand."

Tepper, who supported President Barack Obama in 2008 and Mitt Romney in 2012, said he will vote for Hillary Clinton for president but support Republicans in congressional races.

Tepper noted that Americans face a choice between "two people who have judgment issues" in Clinton and Trump. He said he does not like the Democratic economic platform and hopes the GOP keeps control of Congress.