The U.S. Senate Commerce Committee has sent a letter to Facebook CEO Mark Zuckerberg requesting information regarding claims that the social media platform purposely keeps conservative and right-wing news out of its trending topics section.

The letter asks that Facebook “arrange for your staff, including employees responsible for trending topics, to brief committee staff on this issue,” according to Gizmodo.

Sen. John Thune, a Republican from South Dakota who is chairman of the Committee on Commerce, Science and Transportation, signed the letter. The letter also asks Facebook to describe “organization structure for the Trending Topics feature, and the steps for determining included topics,” and asks, “Who is ultimately responsible for approving its content?”



Also Read: Facebook Claims Censoring Trending Topics Is 'Technically Not Feasible'

The U.S. Senate Commerce Committee has jurisdiction over media issues, consumer protection issues and Internet communication. The Committee also wants Facebook to outline steps the company is taking to investigate claims of politically motivated manipulation of news stories and hold the responsible individuals accountable.

“We have received Sen. Thune’s request for more information about how Trending Topics works, and look forward to addressing his questions,” Facebook said in a statement.

Gizmodo reported on Monday that former Facebook workers said colleagues would prevent conservative topics and publications from appearing in the Trending Topics sidebar next to a users’ primary news feeds.



Also Read: Facebook Claims Censoring Trending Topics Is 'Technically Not Feasible'

Facebook defended its trending news practices, saying that workers on its influential Trending Topics section couldn’t suppress particular news outlets or ideologies because of technical blockers.

Tom Stocky, vice president of search and the head of the Trending Topics team, said in a Facebook post that the company neither allows nor advises Trending reviewers to systematically discriminate against sources. “We’ve designed our tools to make that technically not feasible,” he said.

Drudge Report, Breitbart, Washington Examiner and Newsmax are among the conservative news organizations that the former employees claimed were flagged as suspect by Facebook curators.