US news pioneer Joseph Wershba, one of the inspirations for the film Good Night and Good Luck, has died aged 90.Wershba, whose work helped to end Senator Joseph McCarthy's witch-hunt for US communists in the 1950s, died of complications from pneumonia, CBS said.
Robert Downey Jr played Wershba in Good Night and Good Luck, which was nominated for six Oscars in 2006.
"Joe Wershba was a wonderful man who was a pioneer of broadcast journalism," said Jeff Fager, chairman of CBS News.
Wershba, a news reporter and producer for the network, led a 1954 report on Mr McCarthy for Edward R Murrow's TV news show, See It Now.
The report helped discredit McCarthy, who had falsely accused various celebrities and entertainers of links to communism, including playwright Arthur Miller and film star Charlie Chaplin.
His accusations ruined many careers.
Wershba also worked on 1953's The Milo Radulovich Story, about a reserve officer discharged by the US Air Force because it believed his family had communist sympathies.
His appeal was denied despite the Air Force providing no evidence.
Following the CBS investigation, Radulovich was reinstated.
Wershba is survived by his wife Shirley, a son and daughter and two grand-daughters.