A man in a San Francisco pub claimed he wanted to avenge his daughter's death by killing Queen Elizabeth, according to newly released FBI files.
Details of the purported threat made ahead of the queen's 1983 visit to the US city were passed on to the FBI, concerned at the time about a potential attack by the IRA.
Following the queen's death last year, sources close to the leadership of the IRA in the 1980s told The Irish News it was agreed no attempt would be made on the life of the queen for strategic reasons, though there were dissenters.
According to the files, the assassination threat was made to a police officer in San Francisco.
One officer who drank in an Irish pub in San Francisco told federal agents the man said he was seeking revenge for his daughter who had been killed in Northern Ireland during the Troubles.
The apparent threat was made came in early February, 1983, a month before the queen and her husband Philip's visit to California. The couple visited San Francisco and Yosemite National Park to the east of the state.
"He was going to attempt to harm Queen Elizabeth and would do this either by dropping some object off the Golden Gate Bridge onto the Royal Yacht Britannia when it sails underneath, or would attempt to kill Queen Elizabeth when she visited Yosemite National Park," the document states.
The US Secret Service planned to "close the walkways on the Golden Gate Bridge as the yacht nears".
More than 100 pages of documents related to visits by the queen were uploaded this week to the Vault, the FBI's information website. It followed a Freedom of Information request.
The couple visited Yosemite and spoke with rangers, news reports from the period reveal.
In 1976, during the queen's visit to New York City for the country's bicentennial celebrations, a summons was issued to a pilot for flying a small plane over Battery Park with a sign that read:"England, Get out of Ireland."
