Facebook workers purposely edited conservative news stories out of users’ feeds by ranking them lower down the platform’s trending list, according to a former employee.
The social media giant is accused of routinely directing workers to subvert the prominence of right-wing news stories on Facebook, the worker told Gizmodo.
Facebook created the role of a "news curator" whose job was to artificially "inject" stories high up its trending news section, even if they were not trending, former curators told Gizmodo.
They were also told not to include news about Facebook.
"It was absolutely bias, we were doing it subjectively," a former curator said.
"I believe it has a chilling effect on conservative news."
A recent case in Australia highlighted the influence Facebook’s editors can have when a Sydney academic and Anglican minister had a post on gay marriage accidentally removed.
Dr John Dickson, founder of the Centre for Public Christianity, told ninemsn he believed the post had been deleted in error but would not be surprised if there was not a subconscious bias at Facebook.
"My lengthy conversation with one of the execs at Facebook has convinced me that, while there is probably a left bias, they want to make sure all views get out there," Dr Dickson said.
But if Facebook is manipulating the views that trend, people should be made aware of it so it can be taken into consideration, he said.