The Secretary of State for War, John Profumo, has denied any impropriety with the model, Christine Keeler.
Allegations were made yesterday by three MPs in the House of Commons, that Mr Profumo was in some way connected to the disappearance of Miss Keeler, who was due to appear as a witness in a trial at the Old Bailey.
But in a personal statement to the House today, Mr Profumo, 48, categorically denied the accusations and warned that he would not hesitate to issue writs for libel and slander if the allegations were made outside the House of Commons.
He said: "There was no impropriety whatever in my acquaintance with Miss Keeler and I have made the statement because of what was said yesterday in the House by three honourable members whose remarks were protected by privilege."
Rumours
He went on to explain that he and his wife, the actress Valerie Hobson, had met 20-year-old Christine Margaret Keeler at Cliveden, Berkshire, in July 1961.
The couple had been invited by Dr Stephen Ward, a London osteopath, to his country cottage on the Cliveden estate near the River Thames.
Also at the cottage was Captain Eugene Ivanov, a naval attaché at the Russian Embassy in London.
It is understood Miss Keeler was having an affair with Captain Ivanov at the time.
Rumours began to circulate that Mr Profumo had begun an affair with the young model soon after their meeting and that secret information on nuclear weapons could have been passed via Miss Keeler to Captain Ivanov.
These rumours were the basis of the allegations made by MPs George Wigg, for Dudley, Richard Crossman, for Coventry East, and Barbara Castle, for Blackburn, yesterday.
But in today's statement Mr Profumo said that between July and December 1961 he had met Miss Keeler about half a dozen times at Dr Ward's flat when he had called to see him, but stressed there was "no impropriety whatsoever" in the relationship.
He added he had not seen Miss Keeler since December 1961 and had no part in her disappearance.
Miss Keeler had been due to appear at the Central Criminal Court as a witness in a shooting trial.
But the Secretary of State for War was steadfast in his denial: "Any suggestion that I was in any way connected with or responsible for her absence from the trial at the Old Bailey is wholly and completely untrue."
In Context
On 5 June 1963 Profumo resigned from the government after admitting he had lied to Parliament about his relationship with Christine Keeler.
Three days later Dr Stephen Ward was arrested and charged with living off immoral earnings. His trial took place the following month.
He was found guilty on two charges but he did not live to hear the verdict because he took a fatal drug overdose the night before the judge finished summing up and died four days later.
Many believe Stephen Ward was made a scapegoat to save the government from embarrassment.
The Prime Minister, Harold Macmillan, asked Lord Denning, to conduct an inquiry into security aspects of the Profumo affair.
Lord Denning criticised the government for failing to deal with the affair more quickly, but concluded that national security had not been compromised.
In December 1963 Christine Keeler was arrested and charged with conspiracy to pervert the course of justice and perjury in an unrelated court case. She was sentenced to nine months imprisonment after pleading guilty to the charges.
The scandal rocked Harold Macmillan's Conservative government to its core and eventually led to its downfall when Labour, led by Harold Wilson, came to power in October 1964.
John Profumo died in March 2006.
After leaving politics he dedicated his life to helping the poor and disadvantaged in the East End of London. He was given a CBE in 1975 for services to charity.
The Central Criminal Court of England and Wales, commonly known as the Old Bailey from the street on which it stands, is a court in London and one of a number of buildings housing the Crown Court. Part of the present building stands on the site of the medieval Newgate gaol, on Old Bailey, a road which follows the line of the City of London's fortified wall (or bailey), which runs from Ludgate Hill to the junction of Newgate Street and Holborn Viaduct.
The Crown Court sitting at the Central Criminal Court deals with major criminal cases from Greater London and, in exceptional cases, from other parts of England and Wales. Trials at the Old Bailey, as at other courts, are open to the public, albeit subject to stringent security procedures.