Media Matters for America, a group that aims to "correct conservative misinformation in the U.S. media," has responded to a challenge issued by Rupert Murdoch to show that Fox News is biased.

The group is responding to comments made by Murdoch on Tuesday in an interview with WorldScreen.com, in which the News Corp chief said that Fox is "fair and balanced and we challenge anyone to show FOX News has any bias in it."

In an open letter to Murdoch, MMfA's president and CEO David Brock wrote:

"My organization, Media Matters for America, has been monitoring the U.S. media, including Fox News, for nearly a year. We try to avoid using the term "bias" in describing news coverage, preferring to focus on the observable content of news stories, rather than try to discern the private attitudes of those who produce them, which amounts to speculation. Still, we can't help noticing a pronounced rightward tilt in your channel's news programs."

Brock then linked to the group's database of monitoring items pertaining to FNC.

Murdoch, at the end of the Tuesday interview, said that he identifies as "an independent" and noted that some News Corp-operated newspapers in the US, Australia and the UK have supported left-of-centre parties.