Reporters Bob Woodward, right, and Carl Bernstein, whose reporting of the Watergate case won a Pulitzer Prize, sit in the newsroom of the Washington Post, May 7, 1973. (AP Photo)

PHOTO: EAST NEWS/AFP Picture dated 29 June 1972 of Republican president Richard Nixon pointing to one of the journalists during a press conference in Washington First elected in 1968 and re-elected in 1972, Richard Nixon had to resign in August 1974 after the Watergate scandal.

Investigative reporter and associate editor of The Washington Post, Bob Woodward at his home in Georgetown.

Investigative reporter and associate editor of The Washington Post, Bob Woodward at his home in Georgetown.

Investigative reporter and associate editor of The Washington Post, Bob Woodward at his home in Georgetown.

Investigative reporter and associate editor of The Washington Post, Bob Woodward at his home in Georgetown.

Carl Bernstein, an American journalist who, as a reporter for The Washington Post along with Bob Woodward, broke the story of the Watergate break-in and consequently helped bring about the resignation of US president Richard Nixon. ? Felix Clay / eyevine For further information please contact eyevine tel: +44 (0) 20 8709 8709 e-mail: info@eyevine.com www.eyevine.com

Carl Bernstein, an American journalist who, as a reporter for The Washington Post along with Bob Woodward, broke the story of the Watergate break-in and consequently helped bring about the resignation of US president Richard Nixon. ? Felix Clay / eyevine For further information please contact eyevine tel: +44 (0) 20 8709 8709 e-mail: info@eyevine.com www.eyevine.com

** FILE ** Watergate conspirator G. Gordon Liddy, right, confronts Jack Anderson as they appear on ABC TV's

**FILE** Flanked by Sen. Lowell O. Weicker Jr., R-Conn., left, and Sen. Abraham A. Ribbicoff, D-Conn., right, acting FBI director L. Patrick Gray prepares to testify in this Feb. 1973 file photo before the Senate Judiciary Committee on his nomination as director of the FBI in Washington. Gray, whose yearlong stint as acting FBI director was marked by the Watergate break-in and the ensuing scandal that led to President Nixon's resignation, has died. He was 88. (AP Photo/File)

**FILE** L. Patrick Gray, second from left, is sworn in as assistant attorney general in the Department civil division by U.S. Circuit Judge Roger Robb, right, at a ceremony in the office of Attorney General John N. Mitchell who witnessed, left, in this December 1970 file photo in Washington. L. Patrick Gray, whose yearlong stint as acting FBI director was marked by the Watergate break-in and the ensuing scandal that led to President Nixon's resignation, has died. He was 88. (AP Photo/File)

**FILE** Acting FBI director L. Patrick Gray, speaks in this August, 12, 1972 file photo in Cleveland, Ohio. Gray, whose yearlong stint as acting FBI director was marked by the Watergate break-in and the ensuing scandal that led to President Nixon's resignation, has died. He was 88. (AP Photo/File)

**FILE** Acting FBI director L. Patrick Gray goes through papers as he starts his second day of testimony before the Senate Judiciary Committee in Washington in this March 1973 file photo. L. Patrick Gray, whose yearlong stint as acting FBI director was marked by the Watergate break-in and the ensuing scandal that led to President Nixon's resignation, has died. He was 88. (AP Photo/FIle)

Watergate reporters Carl Bernstein, left, and Bob Woodward talk on the set before their appearance on the NBC-TV

Watergate reporters Carl Bernstein, left, and Bob Woodward, center, are interviewed by NBC-TV

PHOTO: EAST NEWS/AFP US House Judiciary subcommittee members (Top Row L-R) Ed Bryant, R-TN; Bob Inglis, R-SC and US Rep. Henry Hyde,R-IL, chairman of the US House Judiciary Committee along with (Front Row L-R) Steve Chabot, R-OH, and Steve Buyer, R-IN watch tapes of the Watergate hearings during meetings 09 November on Capitol Hill in Washington, DC. The subcommittee is holding preliminary hearings in an attempt to decide what is an impeachable offense in preparation of upcoming House Judiciary Committee impeachment investigation proceedings against US President Bill Clinton. AFP PHOTO Luke/FRAZZA

Senator Sam J. Ervin Jr., (D-N.C)., Chairman of the Senate Watergate Committee debates, July 25,1973 in Washington, D.C. whether the president has the implied power to abridge the fourth amendment in relation to the Ellsberg break in. (AP Photo).

Frank Sturgis, left, looks on as his attorney, Ellis Rubin of Miami, Fla., speaks to reporters at a Washington news conference, March 17, 1986. Sturgis has asked a federal court to reopen his case and clear his name on the conviction 13 years ago on the burglary and wiretapping charges in connection with the Watergate scandal. (AP Photo/Dennis Cook)

Former White House counsel John W. Dean III watches E. Howard Hunt Jr., respond to a question during a news conference at Lafayette College in Easton, Pa., Feb. 24, 1982. Hunt pleaded guilty to organizing the entry team that was arrested in the Watergate offices of the Democratic National Committee in 1972. He served nearly three years in federal prison for his role in the Watergate break-in. (AP Photo)

Dan Rather, right, grins as Walter Cronkite answers questions on Thursday, Feb. 14, 1980 at news conference in New York City. Conference was held to announce that Rather, the ??s60 Minutes??? correspondent who gained national attention with his questioning of Richard Nixon during the Watergate scandal, will succeed Cronkite as anchorman of the ??sCBS Evening News.??? (AP Photo/Jorgensen)