21 May 2014 Last updated at 19:17 BST
The Prince of Wales is reported to have criticised the Russian president, Vladimir Putin, for behaving like Hitler, according to a woman who fled Poland in 1939.
Marienne Ferguson was speaking after she met the prince at an immigration museum in Halifax, Nova Scotia, where she is a volunteer.
Clarence House said it would not comment on a private conversation.
Nicholas Witchell reports.