Facebook has denied allegations that it suppresses U.S. election 2016 news regarding popular conservative issues from appearing on its "Trending Topics" section. The social media giant's CEO addressed the rumors on Thursday.

Earlier this week, Gizmodo reported that a former journalist admitted that Facebook "routinely suppressed news stories of interest to conservative readers." The insider added that workers stopped stories from appearing in the "Trending" section of the platform.

Several of these former "news curators" also admitted that they were told to "inject" select stories into the trending news module. They were also instructed not to include news about Facebook in the section.

"Depending on who was on shift, things would be blacklisted or trending," a former employee said. "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."

According to The Guardian, leaked documents of Facebook showed how the social media giant still relies on human intervention rather than sticking to algorithm to bring the hottest news to its users. This comes in the middle of growing concerns over the platform's alleged U.S. election 2016 news bias.

In a recent report by Gizmodo, Facebook issued a statement to clarify the claims. The company's vice president of global operations, Justin Osofsky, said on Thursday that the topics that can be included in the trending section are first collected by an algorithm that "identifies topics that have recently spiked in popularity on Facebook" but "also uses an external RSS website crawler to identify breaking events."

"We have found no evidence that this report is true," Facebook CEO Mark Zuckerberg said. "If we find anything against our principles, you have my commitment that we will take additional steps to address it."