Former CIA agent Bernard Leon Barker, who took part in the Watergate burglary in Washington more than 30 years ago, has died in Miami at the age of 92.
In the course of a long and colourful career, Mr Barker was also one of the leaders of the failed CIA attempt to invade Cuba at the Bay of Pigs in 1961.
He had suffered from cancer and heart problems, the AP news agency said.
The Watergate break-in sparked one of America's biggest political scandals, toppling then-President Richard Nixon.
Washington Post reporters Bob Woodward and Carl Bernstein played a key role in bringing the scandal to light, aided by crucial information from their mysterious informant, Deep Throat.
Their book on the scandal, All The President's Men, became a movie starring Dustin Hoffman and Robert Redford.
His name was often discussed by American political activists as having played a role in the assassination of John F Kennedy, allegedly in revenge for his failure to fully support the Bay of Pigs invasion.
But he was best known for being one of the five men who broke into the Democratic Party headquarters in 1972 at the Watergate building in Washington, at the behest of Mr Nixon.
The men were attempting to plant wiretaps to spy on the Democrat opponent of Mr Nixon - an event which eventually led to the once-popular president resigning in disgrace two years later.
In his later years, Mr Barker remained unapologetic about his involvement in the Watergate scandal, for which he only served a little over a year in prison.
As an anti-communist activist, he said he remained convinced that Mr Nixon was "one of the best presidents" the United States ever had.