Fonteyn and the plot to overthrow Panama's government

The extraordinary story of the ballerina's role in a coup attempt has been revealed by the National Archives

The planning, like Dame Margot Fonteyn's footwork, seemed meticulous. A yacht was leased by the ballerina and her husband for a "fishing trip" in Panama and a cover story including a meeting with the Duke of Edinburgh was carefully finessed.

But for Britain's most famous dancer, her holiday in April 1959 to the central American state was merely the pretext for an extraordinary and ultimately disastrous attempted coup involving a cast which ranged from Fidel Castro to Errol Flynn – and necessitated some nimble manoeuvring from Her Majesty' Foreign Office when it all went horribly wrong.

The full story of the involvement of the ballerina whose grace enraptured audiences in London's Covent Garden in a violent attempt by her Panamanian husband, Dr Roberto Arias, to overthrow the government of President Ernesto de la Guardia is revealed today for the first time in documents released by the National Archives.

The secret Foreign Office file describes how panic ensued in Whitehall when Dame Margot, then aged 40, was arrested and placed in Panama City's central prison on 20 April. She was detained shortly after she had helped to transfer Dr Arias on to a fishing boat transporting him and a detachment of Cuban mercenaries to a mountain hideaway from where they had planned to launch a revolution.

The arrest of the ballerina, at the time probably Britain's most revered cultural export, led to an outcry in the international media and a swift operation by Sir Ian Henderson, the UK ambassador to Panama, to secure Dame Margot's release. Describing how the dancer had arrived in Panama on 10 April for a fishing vacation that included an "enthusiastically accepted" invitation to meet Prince Philip during a coincidental visit to the country, Sir Ian said the British embassy had been aware of Dr Arias's revolutionary intentions but sought to impress upon the Panamanian authorities that it was better to let his wife go to avoid an international incident. The ambassador, who noted approvingly that the Panamanians had treated their VIP well by putting her in the prison's "presidential suite" with an English-speaking guard who decorated her cell with fresh flowers, was privately scathing of Dame Margot.

In a telegram back to London, he wrote: "She knew that her husband was gun-running, she knew that he was accompanied by rebels and at one point she used her yacht to decoy Government boats and aircraft away from the direction which her husband was taking. I do not regard her conduct as fitting in any British subject, let alone one who has been highly honoured by Her Majesty the Queen."

Dame Margot, whose career was revived three years later when she began her collaboration with Rudolf Nureyev, was eventually released at 1am on 22 April to be placed on a flight to New York and then onwards to London. The file, which underlines the inter-linked nature of British high society in the 1950s, describes how the true nature of the plot, and extent of the ballerina's involvement, was only revealed when she met for drinks with her friend, John Profumo, at the time a junior Foreign Office minister.

Mr Profumo, who was later disgraced by his affair with the prostitute Christine Keeler, wrote: "I had to pinch myself several times during her visit to be sure I wasn't dreaming the comic opera story which unfolded. "It is quite plain that she has been, and still is, deeply involved in Panamanian political matters and in the current crisis there. She admitted visiting Cuba in January and, together with her husband, seeing Dr Castro... She affirmed that even up to a short while ago, Castro was behind this coup."

In a final dispatch, Sir Ian wrote: "Her conduct has been highly reprehensible and irresponsible to a degree. I sincerely hope that her friends and relations will urge her to keep away from Panama for a very considerable time."