Howard Hunt said he was bitter about his imprisonment

Mr Hunt, who was jailed over the incident, had died after a lengthy bout of pneumonia in Miami, his son said.

The accidental discovery of the Watergate burglary snowballed into the country's biggest political scandal.

The conspirators wanted to plant bugs to spy on the Democrats during the Republicans' re-election campaign.

While working for the CIA, Mr Hunt recruited four of the five actual burglars, and always stressed he preferred to be known as the "Watergate conspirator".

Mr Hunt served 33 months in prison for conspiracy, wiretapping and burglary.

He said he was bitter that he had to go to prison while Mr Nixon had been allowed to resign.

'Debt paid'

His co-conspirator G Gordon Liddy was sentenced to four-and-a-half years for the break-in.

Earlier in his life, Howard Hunt served as a destroyer gunnery officer, but was injured at sea and given an honourable discharge from the US Navy.

From 1949 to 1970 he worked for the CIA, and was involved in the operation that overthrew Jacobo Arbenz as Guatemala's president in 1954, and the failed Bay of Pigs invasion in 1961.

He declared bankruptcy in 1997, largely blaming his Watergate fines and legal fees.