A new book has revealed British security services kept a file on the former Labour Prime Minister Harold Wilson throughout his time in office.
Defence of the Realm, the first authorised history of MI5, says there were worries about his relationships with Eastern European businessmen. His contact with KGB officers also raised concerns.
However, the book, which marks MI5's centenary and is being serialised in the Times, dismisses long-standing claims of bugging and plots against him. It says there is no evidence of a plot to either smear or oust him.
Mr Wilson died in 1995 aged 79. Labour leader for 13 years, he led the country from 1964 - 1970 and again from 1974 - 1976.
The BBC reports MI5 opened the dossier in 1945 when Mr Wilson became an MP after communist civil servants suggested he had similar political sympathies.
The book's author, Cambridge professor Christopher Andrew, says
his file was so secret that he was given a pseudonym, Norman John Worthington.
The BBC reports a belief there was a plot against Wilson was fuelled in the late 1980s when a former MI5 officer Peter Wright published his book, Spycatcher.
However, it does not appear as if Mr Wilson was the target of a specific investigation in which his phones or office were bugged.
But Mr Wilson believed he was bugged. When talking to people, he would sometimes gesture to pictures on the wall or to the ceiling.
