The MI5 verdict: Ian McGibbon outlines what Paddy Costello's recently opened MI5 file indicates about why British counter-espionage concluded that he was a Soviet agent.

• Author: McGibbon, Ian
• Position: PADDY COSTELLO

Whatever the truth about Paddy Costellos allegiance, one fact is known: towards the end of his life, MI5 concluded that he was a Soviet agent. There had been suspicions for nearly three decades, of course, but after taking his professorship in Manchester Costello fell off MI5's radar, at least for a time. The focus returned to him in the early 1960s, though not for the commonly supposed reason of his alleged involvement in the Kroger affair--the issue of New Zealand passports to Peter and Helen Kroger (who were in fact Soviet spies Maurice and Leontina Cohen) by the New Zealand Legation in Paris in 1954 when Costello was on the staff; in possession of perfectly forged documents, the Krogers needed no illicit assistance in obtaining the passports. Nothing on Costello's recently released MI 5 file indicates any suspicion falling on him when this was revealed in 1961.

That Costello came under renewed MI5 scrutiny was directly attributable to his wife Bella (Bil). Long known to have been a communist earlier in her life, she was identified as having ordered several children's death certificates in 1960. Acquisition of such documents was known to be a KGB ploy to create false identity documents or passports. She did so under the assumed name B. Green; the address she gave was one she and her husband had had twenty years before in Exeter. This was an amateurish mistake for an agent, but it only became significant because of the alertness and good memory of an MI5 official. Reviewing the application some years later, he recognised the former address of the Costellos when they were under suspicion of being communist agents. (1) A classic example of the value of institutional memory, his discovery convinced MI5 that Bella Costello was a Soviet agent. When apprised of it, the head of New Zealand's Security Intelligence Service, Brigadier Bill Gilbert, agreed that her action was pretty conclusive evidence' against her. (2)

After this MI5 took another look at Paddy Costello. Although no longer having access to government documents, he nevertheless held a position that could be useful to the Soviets, or so counter-espionage officials thought. As an agent of influence, he could encourage students to go to the Soviet Union on cultural exchanges or visits, where they might be suborned or recruited. Both he and his wife were placed Bil I Gilbert under close observation. Transcripts of telephone calls made by Bella Costello are to be found on the file...