Sen. Josh Hawley (R-MO) sent a letter to Facebook CEO Mark Zuckerberg demanding to know why the social media giant throttled a New York Post article that alleged Hunter Biden “facilitated” a meeting between a Ukrainian gas company and former Vice President Joe Biden.

Facebook decided to reduce the distribution of a New York Post article saying that, contrary to Biden’s claims, Biden allegedly met with an executive at Burisma when he was vice president. Hunter Biden, Joe Biden’s son, reportedly arranged the meeting while he was working as a lobbyist for the company.

Fox News reported that the Senate Homeland Security Committee is investigating the claim.

Andy Stone, who works for communications at Facebook and is a former Democrat staffer, said that the social media platform would reduce the story’s distribution until Facebook’s fact-checkers can verify the report.

Hawley slammed Facebook’s decision to quash the virality of the Post story. Hawley wrote in his letter to Zuckerberg:

The seemingly selective nature of this public intervention suggests partiality on the part of Facebook. And your efforts to suppress the distribution of content revealing potentially unethical activity by a candidate for president raises several additional questions, to which I expect responses immediately.

Hawley also demanded to know several questions regarding Facebook’s decision to censor the story, including:

Hawley asked rhetorically on Wednesday, “Did Biden campaign ask you to do so?”

Sean Moran is a congressional reporter for Breitbart News. Follow him on Twitter @SeanMoran3.