The scandal happened at the height of the Cold War when it was discovered that Keeler had been sleeping with both Profumo, the then Conservative Minister for War, and Yevgeny Ivanov, a naval attache based at the Russian Embassy in London.
Keeler and Profumo began their affair after being introduced at a party at the Cliveden estate in 1961 by their mutual friend Stephen Ward, a high-society osteopath and portrait-painter.
Profumo, who was married to actress Valerie Hobson, had no idea that Keeler was also sleeping with Ivanov. In March 1963 he told the House of Commons that rumours of his affair were untrue, but he was forced to resign three months later after admitting he had lied.
Ward, who was prosecuted for living off immoral earnings, took an overdose the day before his trail ended and died on August 3, 1963. Keeler was found guilty of unrelated perjury charges and was sentenced to nine months in prison.