May 30 (Bloomberg) -- Archibald Cox, the special prosecutor in the Watergate probe fired by President Richard Nixon, and Samuel Dash, the chief counsel to the U.S. Senate committee that investigated the scandal, both died yesterday. Cox was 92 and Dash was 79.

The two men were instrumental in the discovery and pursuit of White House tapes proving Nixon and his closest advisers knew about and attempted to conceal the involvement of Republican Party officials in a 1972 burglary at the Democratic Party's headquarters in the Watergate building in Washington.

Dash pressed a White House aide to reveal that Nixon knew of a secret taping system that recorded the conversations of administration officials. Cox's insistence on unfettered access to the recordings while investigating the Watergate burglary and cover-up helped lead to Nixon's resignation in 1974.

``They helped to define acceptable ethical standards in an age in which those standards were sorely lacking,'' said Larry Sabato, director of the University of Virginia's Center on Politics. ``They found a case where a president had violated every acceptable standard, and pursued it at great personal risk.''

Cox, a former Harvard law professor and government lawyer, died yesterday at his home in Brooksville, according to information on the Harvard School of Law's Web Site. The Georgetown University Law Center carried news of Dash's death.

`Saturday Night Massacre'

In May 1973 Cox was appointed as the special prosecutor assigned to conduct an independent investigation of a break-in at the headquarters of the Democratic National Committee in Washington by five men linked to Nixon's re-election campaign.

A Senate investigation into the incident uncovered a White House taping system that recorded conversations of the president and his staff. Cox subpoenaed recordings of conversations in the Oval Office from the period surrounding the break-in.

When Cox refused to accept edited or abridged versions, Nixon ordered him fired.

Attorney General Elliot Richardson, a former student of Cox's who had recruited him as special prosecutor, and his deputy, William Ruckelshaus, resigned instead of complying with Nixon's demand. Robert Bork, who was solicitor general, dismissed Cox on Oct. 20, 1973. The incident, which became known as the ``Saturday Night Massacre,'' hurt Nixon's popularity with the public and his support from fellow Republicans in Congress.

``I remember driving back from Alexandria (Virginia) at two o'clock in the morning almost weeping because I realized that we would be exposing the President of the United States as a criminal,'' Dash said in a 1998 interview with Bar Report, a publication of the District of Columbia Bar Association. ``It was a tremendous burden.''

Cox was replaced by Leon Jaworski, who continued to seek the tapes and eventually got them. The release of the tapes, revelations that White House and Nixon re-election campaign officials were involved and Dash's questioning on behalf of the committee, helped force Nixon to resign.

Dash

Dash, who joined the Georgetown University Law Center in 1965 and served as director of its Institute of Criminal Law and Procedure, grew up in Philadelphia, and began working at age seven, according to the university. At 18 he enlisted in the Army Air Corps and served as a bombardier navigator flying missions in Italy during World War II.

He served as an ethics adviser to Kenneth Starr, who investigated charges President Bill Clinton lied about his involvement with White House intern Monica Lewinsky. Dash resigned from that post in November 1998, saying Starr abused his powers as an investigator by appearing to advocate Clinton's impeachment, the Washington Post reported.

He was also special investigator in 1976 for Pennsylvania in examining the firing of a special prosecutor investigating police corruption in Philadelphia, and in 1985 served as chief counsel to the Alaska Senate during its impeachment inquiry against the governor, according to Georgetown University.

From 1983 to 1992 he served as special counsel to the president of the Senate of Puerto Rico, investigating political murders at Puerto Rico's Cerro Maravilla mountain peak, according to Georgetown University.

The Washington Post reported that Dash died of multiple organ failure. Dash is survived by his wife of 57 years, Sara, and two daughters, Judi and Rachel, according to the Post.

Cox

The New York Times reported Cox died of natural causes.

Born in 1912, Cox graduated from Harvard University in 1934 and from Harvard Law School in 1937, according to the university's Web site.

After graduation, he joined the Boston law firm of Ropes, Gray, Best, Coolidge and Rugg, according to the Institute of Government and Public Affairs at the University of Illinois. He began his government career during World War II when he was appointed to the National Defense Board, then to the Office of the Solicitor General, the institute said on its Web site.

A professor at Harvard Law School since the end of World War II and an expert in torts, administrative law and constitutional law, Cox frequently took breaks from teaching to perform public service legal work, according to Harvard Law School.

While teaching at Harvard, he became a speechwriter and adviser to John F. Kennedy, then a senator from Massachusetts. When Kennedy was elected president, Cox took a leave of absence to join the administration as solicitor general.

Professor Cox's great-grandfather, William Maxwell Evarts, defended President Andrew Johnson during impeachment proceedings in 1868, according to the University of Illinois.

To contact the reporter on this story: Joe Richter in Washington jrichter1@bloomberg.net.

Last Updated: May 30, 2004 12:01 EDT