Newly declassified MI5 papers show that Profumo, the key figure in the series of lurid disclosures which in 1963 helped to hasten the downfall of the Conservative government, had a long-running relationship with a glamorous Nazi spy who may have later tried to blackmail him.
The politician had used House of Commons notepaper to compose intimate letters to the woman, a fashion model named Gisela Klein, whom he had met at Oxford in the early 1930s and who had gone on to work for German intelligence during the Second World War.
Ms Klein’s American husband claimed in 1950 that Profumo’s love letters to her had led to their separation.
Intelligence officials knew of Profumo’s colourful love life at the time of the 1963 scandal and issued warnings in Whitehall, the newly-released papers reveal.
The mysterious Ms Klein, who used the married name Winegard and a number of other aliases, had been absent from previously-released British Intelligence documents, though American CIA papers appear to show that she was under MI5 surveillance.
However, it is disclosed today that the Dusseldorf-born model had been “on intimate terms with the German Military Attache in Paris” in 1938, leading the Home Office to recommend she be barred from entering Britain.
The papers also reveal that she ran a secret wartime information service for the Nazis in Paris, under the cover of a “commercial information bureau”, and was the mistress of, and had a child with, a high-ranking German officer.
After the liberation of Paris, she was jailed for espionage but was released when she married Edward Winegard, her US Army jailer. At around the same time, she was accused of harbouring the fugitive former head of a German spy ring in the south of France, and was sacked by the Voice of America radio station when her “pro-German sympathies” and imprisonment were revealed.
Profumo had maintained what MI5 refers to as “an association” with Ms Klein throughout the period, and sent her “endearing letters” from the Commons.
At the height of the 1963 scandal, MI6 officer Cyril Mackay sent a letter and files to MI5 about their liaison. The paperwork, he wrote, “makes mention of an association between Gisela Klein and Profumo which began in 1933 and had apparently not ceased at the time of this report”.
Mr Mackay goes on to discuss a rejected 1951 visa application by Ms Klein for a six-week “pleasure visit”, in which she listed Profumo as a reference.
At the time of the application, the MI6 letter reveals, authorities believed the Winegards had “recently engaged in blackmail activities and now think it possible their intended visit to the UK may be connected with this”. The papers do not say who the intended target of their blackmail efforts have might been.
Profumo, who four years later was to marry the actress Valerie Hobson, volunteered information to MI5 about Ms Klein, the archives reveal.
A memo records that in 1941 he admitted meeting her in 1936 “and got to know her well”.
The memo goes on: “She was always hard up. Later she went on to become a mannequin (model) and made a large number of useful contacts.
“Lady Astor is alleged to have expressed the opinion that she was a spy.”
Profumo was considered prime blackmail target in 1963 when it was revealed that while Secretary of State for War, he had shared a mistress, the showgirl Christine Keeler, with a Soviet defence attache. Profumo was said to have been introduced to Miss Keeler during a party at Lord Astor’s country mansion, Cliveden.