Billionaire investor and Donald Trump-backer Peter Thiel was among those advising Facebook CEO Mark Zuckerberg not to fact-check political ads, according to a new report by The Wall Street Journal.

The Facebook board member and Palantir co-founder pushed for the company's controversial policy, which has been the subject of debate inside and outside Facebook, the Journal reported, citing unnamed sources. Zuckerberg has publicly argued that Facebook should not be the one to decide which claims are true when it comes to political ads, while critics say that stance will allow misinformation to continue to thrive on the platform.

Thiel has reportedly bumped heads over politics with other directors on Facebook's board. In 2016, after Thiel delivered a speech supporting Trump at the Republican National Convention, director and Netflix CEO Reed Hastings told Thiel in an email that his support of Trump demonstrated "catastrophically bad judgment," The New York Times reported. Both Hastings and former White House chief of staff Erskine Bowles, will not stand for reelection to the board, Facebook previously announced. Bowles also has had tensions with Thiel in the past, sources told the Journal.

Conservatives have accused Facebook and other Silicon Valley tech companies of lacking an ideologically diverse workforce. Lawmakers have threatened to crack down unless tech companies can prove that their processes and algorithms are not biased against conservative viewpoints. Thiel's position on the board helps Facebook make the case that it accepts a range of perspectives.

"Many of the decisions we're making at Facebook come with difficult trade-offs and we're approaching them with careful rigor at all levels of the company, from the Board of Directors down," a Facebook spokesperson said in a statement to CNBC. "We're fortunate to have a Board with diverse experiences and perspectives so we can ensure debate that reflects a cross section of views."

Read the full report at The Wall Street Journal.

Subscribe to CNBC on YouTube.

WATCH: Why Facebook's business model is only now coming under fire