Anderson had Parkinson's disease, the Washington Post reported.
Anderson's investigative reporting at one time appeared in about 1,000 U.S. newspapers with 45 million daily readers, the Post said.
Among the major news stories he broke were the Keating Five congressional ethics scandal; the Iran-Contra scandal; the CIA-Mafia plot to kill Fidel Castro; the final days of Howard Hughes and the Iranian connection to the bombing of the U.S. Embassy in Beirut.
He received a Pulitzer Prize in 1972 for his reporting of the U.S. government's tilt from supporting India to Pakistan.
Anderson hired scores of interns and unpaid associates through the years and tutored them in the craft of investigative reporting. Some of his former pupils included Fox TV's Brit Hume, Tony Capaccio of Bloomberg News Service, Howard Kurtz and Jonathan Krim of The Post and novelist Les Whitten.
He received the Society of Professional Journalists/Sigma Delta Chi "Service to Journalism" award in 1987 and is in the Journalism Hall of Fame.
He is survived by his wife of 56 years, Olivia Farley Anderson, and nine children, 41 grandchildren and seven great-grandchildren.