Ronnie Kray and Tory peer Lord Boothby 'attended homosexual parties'
An association between Conservative peer Robert Boothby and London gangster Ronnie Kray was the subject of an MI5 investigation, documents have revealed.
The men went to "homosexual parties" together and were "hunters" of young men, declassified MI5 files claim.
Allegations in 1964 about the pair's relationship caused such concern within Downing Street that the then head of MI5 was summoned to the Home Office.
The government feared a scandal greater than the so-called Profumo Affair.
Rumours that notorious gangster Kray and Lord Boothby - a popular TV presenter and former MP for East Aberdeenshire - were having an affair were published in 1964.
The Sunday Mirror - which did not name the pair - claimed to have a photo of Kray and Boothby together with the bisexual peer's chauffeur and lover, Leslie Holt.
The men were later identified in a German magazine.
Lord Boothby publicly denied having a homosexual or any other close relationship with Kray.
At the time, he said the photograph showed them discussing "business matters", dismissing rumours about his personal life as a "tissue of atrocious lies".
The Sunday Mirror ended up paying £40,000 in damages to Boothby.
But the papers - released as part of 400 declassified files by the Security Service (MI5), Foreign Office and Cabinet Office - reveal new information about their association.
They show how home secretary Henry Brooke was so concerned about the matter he summoned the head of MI5, Sir Roger Hollis, to ask what the security services knew.
Brooke feared the allegations might erupt into a scandal to rival the Profumo affair, which helped to bring down the Conservative government of Harold Macmillan.
Sir Roger told the home secretary how MI5 had received reports that Lord Boothby was bisexual and had contacts with the Krays.
But, since he had no access to official secrets, MI5 concluded that Boothby's private life was of no concern, the papers reveal.
According to an MI5 source, Lord Boothby was in a relationship with Holt - his chauffer and ex-boxer who also went by the name Johnny Kidd.
Holt told the source how Lord Boothby and Kray had "been to a couple of (homosexual) parties together".
The report suggested the Sunday Mirror was tipped off about the "affair" between Lord Boothby and Kray by the rival Nash gang.
The MI5 report said: "Certainly the suggestion that Boothby has been having an affair with the gangster Kray is hardly true."
'A huge scandal'
Dr Richard Dunley, records specialist at the National Archives, said the story was "one of the greatest scandals that never was".
"If this had come out in 1964 it would have been a huge scandal," he said.
Dr Dunley said the files do not mention well-known claims that Lord Boothby had a long-term relationship with former prime minister Harold Macmillian's wife.
"As tabloid headlines go, you can imagine what would have happened," he said.
"The Mirror did effectively get hold of the story but couldn't publish it, they got sued for libel."