There were also jewish refugees that were not allowed into Canada. Afair, the bigger arsehole in that story was the UK, that panicked and decided that everyone who fled Germany during some 193x–194x must certainly be a german spy. They forcefully moved people to camps, and also to foreign territories, but it didn't work terribly well with Canada, too.

I though this to be the article I first heard this story from, but it doesn't seem to address that. Here I found some more details, e.g. on how refugees were in prisoner of war camps along with actual nazis.

Edit: But those are likely not related to the question of what Canada did to become example of how Geneva convention should be, so maybe an unnecessary info ¯\_(ツ)_/¯