NEW YORK — Following several stories questioning Bill O’Reilly’s past reporting, a liberal media watchdog has ordered its researchers to comb through years of the Fox News Channel host’s writings, radio and television shows and public appearances to find examples of inconsistencies.

O’Reilly is squarely in the crosshairs of Media Matters for America, an illustration of how the media is subject to the same political campaigns as politicians. Fox is standing behind O’Reilly, but the extent to which cable news’ most popular personality is damaged may depend on how many more stories come out.

“It’s a moving target,” said Bradley Beychok, Media Matters president.

The effort began a week ago, after Mother Jones magazine reported that O’Reilly claimed to be in a “war zone” while reporting on the Falklands War in Argentina more than 30 years ago for CBS News, when instead he covered an anti-government demonstration more than 1,000 miles away from the front.