New claim of Deep Throat's identity

One of the most mysterious figures in American political history may finally have been revealed yesterday when Mark Felt, a former assistant director of the FBI, was named in print as Deep Throat, the anonymous source whose Delphic encouragement to two young Washington Post reporters helped crack the Watergate scandal and bring down President Richard Nixon.

He is named in a forthcoming book, The Bureau, The Secret History of the FBI, by Ronald Kessler, a former investigative reporter at the Washington Post, according to a rival newspaper, the Washington Times.

The claim coincides with a bout of hype from a rival author, Nixon's former White House counsel John Dixon, a central figure in the scandal, who is planning to mark the 30th anniversary of the Watergate break-in next month by naming his candidate for Deep Throat on the internet.

Bob Woodward and Carl Bernstein, the two reporters and the only people who definitely know Deep Throat's identity, have said they will only reveal the source when he or she is dead.

Various suspects have died since 1972, but Mr Felt is alive, though ill, in California. Woodward is reported to have visited him at home three years ago and Nora Ephron - Bernstein's ex-wife - has apparently long been convinced that he is Deep Throat. So to, according to some Watergate scholars, was Nixon.

At the time of Watergate, Mr Felt was the No 3 official at the Bureau but had just been passed over for the top job on the death of the long-serving J Edgar Hoover.

Various other candidates have been trumpeted over the years, including the White House chief of staff Al Haig.

Some doubt that Deep Throat existed and believe he was a composite dreamed up by Woodward and Bernstein to add credibility and drama to their story.

It certainly worked. They pursued the story, which began with an apparently routine burglary at the Democratic party offices, until it became clear that it was authorised by senior White House officials and covered up by the president. In 1974 Nixon became the first US president to resign.