The questions and revelations over assassination of JFK as unseen records are releasedThe revelation was made in papers relating to the killing, which happened on November 22 1963.
A memo to the director of the FBI said the anonymous phone call was made to the senior reporter at the Cambridge News at 6.05pm on the day Kennedy was shot in Dallas, Texas.
The document, from deputy director James Angleton, said: "The British Security Service (MI-5) has reported that at 1805GMT on 22 November an anonymous telephone call was made in Cambridge, England, to the senior reporter of the Cambridge News.
"The caller said only that the Cambridge News reporter should call the American Embassy in London for some big news and then hung up."
President Kennedy was shot as he rode in a presidential motorcade in Dealey Plaza at 12.30pm Central Standard Time, which is six hours behind Greenwich Mean Time.
The memo added: "After the word of the President's death was received the reporter informed the Cambridge police of the anonymous call and the police informed MI-5.
"The important point is that the call was made, according to MI-5 calculations, about 25 minutes before the President was shot.
"The Cambridge reporter had never received a call of this kind before and MI-5 state that he is known to them as a sound and loyal person with no security record."
The memo added that similar anonymous phone calls "of a strangely coincidental nature" had been received by people in the UK over the past year "particularly in connection with the case of Dr Ward" - potentially a reference to Dr Stephen Ward, one of the central figures in the Profumo affair.
A copy of the memo, dated November 26 1963, was released by the National Archives in July this year, but had gone unreported until the latest batch of documents pertaining to the Kennedy assassination were released on Thursday evening.