In July 1946, she was identified by the
Kellock-Taschereau Commission into espionage as a member of a communist cell, and of having aided the transmission of secret information to the Soviet Union. The Royal Commission had been called by Prime Minister
Mackenzie King in early 1946 to examine allegations of a Soviet spy ring operating in Canada involving military and government officials by
Igor Gouzenko, a Russian cipher clerk stationed in Ottawa, who had defected the previous year. Testifying at Commission hearings, Chapman admitted to being a member of a number of study groups discussing among other things, socialist and
Marxist literature. She was formally charged on 18 September 1946, and surrendered to police the next day to be
arraigned before a magistrate and released on $2,000 bail. After only 4 ½ hours of testimony, County Court Judge A.G. McDougall dismissed the case against the 39-year-old economist, agreeing with the defence counsel that "there was no evidence on which a jury could possibly have convicted." Most tellingly, Gouzenko himself did not recall her name in Soviet documents, and did not recognise her despite living on the same street. Although Chapman was acquitted, she was ostracised from the Canadian Civil Service. She had hoped to get back to working on Canada's national accounts but this was not to be. During the crisis, she had applied for a permanent position at the
Dominion Bureau of Statistics to do essentially what she had already been doing. Although the job competition was delayed until after she had been cleared, the position was given to a less qualified and less experienced man. The Bank of Canada also failed to support her, and Chapman quit. She stated, "Despite my acquittal by the courts, I find it impossible to continue satisfactorily to work in my own field at present." Fortunately, her former boss and friend at the Bureau put her in touch with Cambridge University in England which quickly hired her so that she could continue her national accounting research. She went on to spend three years at
Cambridge University when it was the epicentre of postwar national accounting. Chapman wrote a study of British wages and salaries in the interwar period, which was published in 1953 by
Cambridge University Press as
Wages and Salaries in the United Kingdom, 1920–1938. She returned to Montreal to work in a left-wing research consultancy with another former Bank of Canada employee and fellow exonerated accused spy, Eric Adams. Their firm applied
National Accounting to the needs of unions and workers. ==Personal life==