(Reuters) - NBC News anchor Brian Williams has canceled a planned appearance with late-night talk show host David Letterman this week, an NBC News source said on Sunday, the latest fallout over misstatements by Williams over his experience reporting on the Iraq war.
Williams, a star anchor who has garnered high ratings for the network, said on Saturday that he would voluntarily take himself off the evening newscast for several days while NBC looks into an issue that has damaged his credibility.
The NBC source said Williams, whose return date to the nightly news has not been announced, would not be appearing on Thursday's Late Show with David Letterman.
NBC, a unit of Comcast Corp, on Friday said it was launching an internal probe of Williams over his statements that he was aboard a helicopter in 2003 that was brought down by enemy fire during the U.S. invasion of Iraq.
Williams, who has told the tale repeatedly over the years, has escaped close scrutiny over the remarks until recently. He apologized this week, saying he "misremembered" the incident, an explanation that prompted military personnel and other journalists to call for his resignation. Williams has also been widely derided on social media.
"As his profession shrinks and softens, Williams felt compelled to try to steal the kind of glory that can only be earned the hard way," columnist Maureen Dowd wrote in the New York Times on Sunday.
Also on Sunday, Elizabeth Spayd, editor and publisher of Columbia Journalism Review, told ABC's News's "This Week with George Stephanopoulos" that NBC should have an outside expert carry out an investigation of Williams' statements.
"I don't think that there's going to be enough credibility that gets attached to that kind of an investigation when the people doing it … that have personal connections, personal relationships with Brian Williams," Spayd told ABC News's "This Week with George Stephanopoulos." "They work for a network … that has a lot at stake."
NBC News declined comment over the Letterman cancellation.
The controversy has embroiled NBC's news division as it battles other networks for ratings on nightly news broadcasts.
Williams is also facing scrutiny over his statements about covering Hurricane Katrina in 2005, including assertions he saw a body float by the Ritz Carlton hotel in New Orleans where he stayed and that he got dysentery from the flood water.
Reporting by Karen Brooks in Austin, Texas; editing by Andrew Hay