of MI5 examined the archives and conducted interviews with surviving witnesses. She produced a long account of the affair, but the paper ultimately proved unpublishable because it contained sensitive operational and personnel information. Nevertheless, Bagot's work proved important as a secondary source when the Foreign Office revisited the matter three decades later. In the first two months of 1998, growing rumors of a forthcoming book on the true origins of the Zinoviev letter, based on information from Soviet archives, led to renewed press speculation and parliamentary questions. In response, British Foreign Secretary Robin Cook announced on 12 February 1998 that, in the interests of openness, he had commissioned the historians of the Foreign and Commonwealth Office to prepare a historical memorandum on the Zinoviev letter, drawing upon archival documents. A paper by the Chief Historian of the Foreign and Commonwealth Office, Gill Bennett, was published in January 1999 and contains the results of this inquiry. Bennett had free and unfettered access to the archives of the Foreign Office, as well as those of the Secret Intelligence Service (SIS) and MI5. She also visited Moscow in the course of her research, working in the archives of the Executive Committee of the Communist International, the Central Committee of the Communist Party of the Soviet Union and the Comintern archive of the Communist Party of Great Britain. Although not every operational detail could be published because of British secrecy laws, the publicly available extracts of Bennett's paper still provided a rich account of the Zinoviev letter affair. Her report showed that the letter contained statements very similar to those made by Zinoviev to other communist parties and at other times to the CPGB, but at the time of the letter (when Anglo-Soviet trade talks were taking place and a general election was impending), Zinoviev and the Soviet government had adopted a more restrained attitude towards propaganda in Britain. Despite her extensive research, she concluded "it is impossible to say who wrote the Zinoviev Letter", though her best guess was that it was commissioned by White Russian intelligence circles from forgers in Berlin or the Baltic states, most likely in Riga. It was then leaked to the papers, probably by MI6, that she had stated, "I have my doubts as to whether [Desmond Morton] thought it was genuine but he treated it as if it was." In 2006, Bennett incorporated some of her findings