NEW YORK -- Jack Newfield, a muckraking columnist at several New York newspapers and the author of 10 books on topics ranging from Robert F. Kennedy to boxing impresario Don King, died late Monday at Columbia-Presbyterian Medical Center of kidney cancer that had spread to his lungs. He was 66.
Mr. Newfield's career included stints at the Village Voice, the Daily News, and the New York Post. Most recently, he was a columnist at the New York Sun.
''I think he invented a whole new form of journalism, a new form of personal investigative journalism that was rooted in a consuming ethic and a brilliant search for truth," said Wayne Barrett, Mr. Newfield's longtime colleague at the Voice and his coauthor on ''City for Sale: Ed Koch and the Betrayal of New York."
''He was my journalistic father even though he was only six years older than me," Barrett said. ''His hand has always guided my fingers across the keys."
Mario Cuomo, the former New York governor, who knew Mr. Newfield for some 30 years, said, ''The Greeks say the greatest gift the gods can give a person is a great passion. . . . He was copiously blessed by the gods. His life was all passion."
Mr. Newfield was born in Brooklyn in 1938 and grew up worshiping the Dodgers and Jackie Robinson, who integrated the major leagues in 1947. ''He was the first outsider/underdog I identified with," Mr. Newfield said in 2000.
He graduated from Boys High School and Hunter College, where he majored in journalism.
Like many idealistic young people, Mr. Newfield was drawn to the civil rights movement in the South. He was arrested at a sit-in in 1963 and spent two days in jail with Michael Schwerner, who was later murdered along with James Chaney and Andrew Goodman.
In 1964 Mr. Newfield went to work for the Voice, one of whose founders, Norman Mailer, was among his journalistic models.
His first book, ''A Prophetic Minority," published in 1966, was about his experiences in the civil rights movement in Mississippi.
Mr. Newfield traveled with Kennedy during his presidential campaign and was present at the Ambassador Hotel when the candidate was assassinated on June 5, 1968.
His second book, ''Robert Kennedy: A Memoir," came out the following year.
''Though it's really unknowable, I think that if Bobby had lived to be president we would have ended the Vietnam War much sooner, renewed the war on poverty; we would have had a totally different policy toward blacks than Richard Nixon had," Mr. Newfield had said in an interview.
Mr. Newfield was at the Voice as a columnist, reporter, and senior editor until 1988. He was a columnist at the Daily News from 1988 to 1990 and at the Post from 1991 to 2001.
At the time of his death he was a fellow at The Nation Institute and a columnist for the Sun.
His later books included ''Only in America: The Life and Crimes of Don King," ''Somebody's Gotta Tell It: The Upbeat Memoir of a Working Class Journalist," and ''The Full Rudy: The Man, the Myth and the Mania," about former mayor Rudolph Giuliani.
Mr. Newfield also worked on several television documentaries as a writer and producer, and he published numerous articles for The Nation, Parade, New York magazine, and other publications.
''Jack never forgot where he came from," said Nation publisher Victor Navasky. ''Everything he wrote was on behalf of the dispossessed and we were honored to be able to publish him in his last years and proud that the late Nation editor Carey McWilliams helped discover him in his early years."
Mr. Newfield won several journalistic honors, including a George Polk Award in 1980 for his reporting on state and city politics at the Voice. He won an Emmy in 1991 for a documentary, ''Don King: Unauthorized," that aired on PBS.
Mr. Newfield, who lived in New York, leaves his wife, Janie, and children Rebecca and Joseph.
Funeral services were planned for today at Riverside Chapel on West 76th Street.