424 • PONTECORVO, BRUNO
xie`me Bureau and the Polish Cipher Bureau, and after the Nazi
occupation both were accommodated in England at Woldingham in
Surrey and made an impressive contribution to the Allied victory.
After the war, the Poles cooperated with SIS’sSpecial Liaisonsec-
tion and concentrated on Soviet wireless traffic.PONTECORVO, BRUNO.A brilliant, dashing, and popular experi-
mental physicist, Italian-born Bruno Pontecorvo was unquestionably
a Communist, as was most of his family, his cousin Emilio Sereni
being a Communist senator in Rome, his brother a successful movie
director, and his brother-in-law Duccio Tabet a member of the Ag-
ricultural Staff of the Italian Communist party. Despite this, he had
worked on the Manhattan Project during World War II and was au-
thorized to work at the Chalk River atomic plant in 1946. After the
defectionof Klaus Fuchs, however, Sir John Cockcroft had told him
that his security clearance at Harwell, where he had worked since
1948, would be withdrawn and that he ought to take up the post of
professor of physics at Liverpool University. Instead, Pontecorvo
dramatically demonstrated his political commitment by defecting
with his Swedish wife Marianne and three sons to Russia via Finland
in September 1950. His route also indicated some use of Soviet
tradecraft, for he purchased his airline tickets while on vacation in
Rome only at the last moment, using cash, leaving his parents waiting
at Chamonix, where he had arranged to join them for a skiing week-
end. Instead Pontecorvo and his family flew to Copenhagen, caught
a ferry to Stockholm, and then flew to Helsinki, where they were seen
being met at the airport by a limousine.
Up until that time,MI5had had no reason to believe Pontecorvo
was a Soviet spy, although he had been a possible candidate for
quantum, a physicist in thevenonatraffic who had volunteered to
supply information from the Manhattan Project. A text dated 21 June
1943 from the Washington, D.C.,rezidenturanoticed that on 14 June
quantumhad visited the Soviet Embassy in Washington, asking to
see the ambassador, and had been introduced to Maxim Litvinov’s
deputy, Andrei Gromyko, who then held counselor rank; Gromyko
had promptly passed him on toegorfrom therezidentura.quan-
tum’s purpose was to explain that he had already sold some informa-
tion to Semyon Semyonov in New York and now wanted to sell some