Former New Mexico Gov. Gary Johnson, a candidate for the Libertarian party's nomination for president, is disputing a report that billionaire Republican David Koch has agreed to bankroll his campaign.

"We have no knowledge of it," Johnson told CBS News when asked about the report, which first appeared on The Daily Caller, a conservative news site. "None whatsoever."

"You just got to laugh," Johnson added, chuckling.

Get Breaking News Delivered to Your Inbox

A spokesman for the Kochs was likewise dismissive.

"Reports that we are supporting or considering supporting any third party presidential candidate are false," Philip Ellender told CBS News.

Johnson was the Libertarian nominee for president in 2012, and recently made former Republican Massachusetts Gov. William Weld his running mate. The Libertarian nominee will be decided at the party's convention in Orlando at the end of the month.

The Daily Caller report cited "a source within Johnson's campaign" saying that Koch, one of the most prominent political donors in the country, had pledged to support Johnson's campaign with "tens of millions of dollars."

While Johnson is facing stiff competition from tech entrepreneur John McAfee and activist Austen Petersen for the nomination, a Fox News poll released Wednesday found Johnson with 10 percent support nationally in a match-up with Democrat Hillary Clinton and Republican Donald Trump.