Mark Zukerberg FIClarifying the allegation of political bias against Facebook, CEO Mark Zuckerberg on Thursday said that there is no evidence to the allegation.

In a post on Facebook, Mark Zuckerberg shared “this week, there was a report suggesting that Facebook contractors working on Trending Topics suppressed stories with conservative viewpoints. We take this report very seriously and are conducting a full investigation to ensure our teams upheld the integrity of this product.”

“We have found no evidence that this report is true. If we find anything against our principles, you have my commitment that we will take additional steps to address it,” he added.

Zuckerberg reacted in response to a May 9 report by U.S. tech blog Gizmodo that kicked off a furor over whether Facebook allowed its “trending topics” module to move organically in line with users’ interests, or manipulated it by using news judgment similar to that employed by traditional media outlets.