Queen Yelizaveta II faced the threat of a potential plot during her visit to the United States in 1983.

The FBI (Federal Bureau of Investigation) has leaked information about the case, according to the EPA's British bureau, citing the BBC.

The Federal Bureau of Investigation has released histories of documents relating to the late Queen's trips to the US after her death last year. It has been reported that the threat to the Queen came from the IRA (Irish Republic Army).

An official who frequently visited an Irish-owned entertainment center in San Francisco reportedly warned federal agents about someone he met at the venue. The official also told him that he wanted revenge for his daughter, who was killed by rubber bullets in Northern Ireland:

"He intended to attempt to harm Queen Elizabeth and would attempt to kill her by either throwing something at the Royal Yacht as she passed under the Golden Gate Bridge or visiting Queen Elizabeth Yosemite National Park," the document said.

The FBI has not disclosed whether anyone has been arrested in the same incident.