Facebook’s Mark Zuckerberg is facing a US Senate inquiry over claims that the social network has been filtering conservative news.

Facebook CEO Mark Zuckerberg has fallen under scrutiny from a US Senate committee over the alleged political bias of the site’s Trending news feature. A GOP senator questioned Facebook’s practice of filtering news, accusing it of “misleading” the public.

The chairman of the Senate Committee on Commerce, Science and Transportation, Senator John Thune, has asked Zuckerberg to answer questions regarding allegations that Facebook’s team prevented conservative news stories from appearing in its Trending news section.

“If Facebook presents its Trending Topics section as the result of a neutral, objective algorithm, but it is in fact subjective and filtered to support or suppress particular political viewpoints, Facebook’s assertion that it maintains ‘a platform for people and representatives from across the political spectrum’ misleads the public,” Thune wrote, stressing Facebook’s “enormous influence on users’ perceptions of current events, including political perspectives.”

Facebook workers routinely prevented conservative news from trending – former employee https://t.co/F9DfryxWNWpic.twitter.com/cl68mO00lj — RT America (@RT_America) May 10, 2016

Zuckerberg has until May 24 at the latest to provide his response for the committee’s inquiry. In his letter, Thune has also asked the social network giant’s CEO to “arrange for your staff, including employees for Trending Topics, to brief committee staff on the issue.”

Thune’s questions range from covering Facebook’s organizational structure to “steps for determining included topics” into its news curation to the network’s management probe into claims about its team’s politically motivated filtering of news.

“Have Facebook news curators in fact manipulated the content of the Trending Topics section, either by targeting news stories related to conservative views for exclusion or by injecting non-trending content?” Thune asked.

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In another question, the GOP senator asked what would be Facebook’s next “steps to hold the responsible individuals accountable” should the allegations be “substantiated.”

The senator also questioned Facebook’s statement issued Monday, following Gizmodo’s report exposing the “news curator” removing right-wing topics such as Mitt Romney, Rand Paul and the Conservative Political Action Conference from making the site’s Trending news list.

Facebook rebuffed the allegations saying that its “guidelines do not permit the suppression of one viewpoint or another or one news outlet or another.”

“How does Facebook determine compliance with these guidelines,” Thune asked.

Thune requested that Facebook provide a list of stories removed from the Trending Topics list since January 2014, along with whether the company has been monitoring such decisions. He asked the company to als share statistics about how many of the injected stories had not in fact been trending.

Facebook has released a statement in response to the committee’s inquiry, stating that it “looks forward to addressing” Thune’s questions. The company has vowed to “take immediate steps to fix” its operational practices if they are “inadequate.”

Here's Facebook's latest statement in full. pic.twitter.com/11u1U8Ok9W — Brian Stelter (@brianstelter) May 10, 2016

The Senate Committee’s inquiry came a day after anonymous former Facebook employees accused the social media network of bias in news reporting.

“Depending on who was on shift, things would be blacklisted or trending,” a former curator told Gizmodo. “I’d come on shift and I’d discover that CPAC or Mitt Romney or Glenn Beck or popular conservative topics wouldn’t be trending because either the curator didn’t recognize the news topic, or it was like they had a bias against Ted Cruz.”

“I believe it had a chilling effect on conservative news,” he added.