Klaus Fuchs - a known communist?

My father was interned while a student at Cambridge in 1940 and sent to Camada. He told us that Klaus Fuchs was on the same ship also being interned after Churchill came to power following Dunkirk. He said that there were 3 groups being sent over, Jews, Nazis and non-Jewish anti Nazis. Fuchs was neither a Jew nor a Nazi and in fact was well known by fellow internees to be a Communist.
The Canadians were appalled to receive Jews and anti-Nazis labelled “enemy aliens” and witin a few months most were redeployed into the war effort. I believe that Klaus Fuchs was sent straight from Canada to the Manhatten Project in the US while my fater returned to the UK by boat to resume his studies, and subsequently worked in the scientific civil service for the Admiralty on Sonar.
How come the US vetting did not reveal Klaus Fuchs’ Communist affiliations which were so widely known among the refugee community?

1 Like