US: Three top executives and a deputy producer at CBS News have been fired for their role in broadcasting a disputed report about President Bush's National Guard service just weeks before the presidential election in November.
Their dismissal comes after an independent investigation found that a "myopic zeal" led 60 Minutes to air the story critical of Mr Bush's 1970s military service on the basis of unauthenticated documents.
However, the inquiry discounted charges that the network was politically biased against Mr Bush. CBS fired producer Mary Mapes, who was a key figure in breaking the Abu Ghraib scandal earlier last year, executive producer Josh Howard, his deputy Mary Murphy, and senior CBS vice president Betsy West.
Veteran CBS presenter Dan Rather, who narrated the report, announced in November he was stepping down as anchor man of the evening news, while insisting the timing was coincidental.
The CBS story is the latest in a series of scandals to shake the US media. Top editors at the New York Times and USA Today were forced to step down because of stories invented by reporters. This week Tribune Media cancelled the syndicated column of conservative African American commentator Armstrong Williams after it was revealed that he promoted Bush administration policies without revealing that he had been paid $240,000 to do so.
The CBS story relied on four documents allegedly written by now-deceased Texas Air National Guard commander, Lieut Col Jerry Killian, raising questions about Mr Bush's conduct as a National Guard pilot.
While the investigation, led by former attorney general Dick Thornburgh and former AP president Louis Boccardi, declined to brand the Killian documents as an outright forgery, it raised serious questions about their authenticity and the way CBS News handled them.
Ms Mapes was also faulted for calling Joe Lockhart, a senior official in the John Kerry campaign, prior to the airing of the piece, and offering to put him in touch with retired National Guard Lieut Col Bill Burkett, who provided the documents.