Prince Charles likened Russia's President, Vladimir Putin, to Adolf Hitler, according to a report.
The Prince of Wales made the accusation during a tour of Canada, where he spoke with a woman who had fled from the Nazis.
"But I was very surprised that he made the comment as I know they [members of the Royal Family] aren’t meant to say these things."'
The woman, Marienne Ferguson, 78, later said: "The Prince said, 'And now Putin is doing just about the same as Hitler.'"
"I must say that I agree with him and am sure a lot of people do,” Ferguson said. "But I was very surprised that he made the comment as I know they [members of the Royal Family] aren't meant to say these things.”
A spokesman for the prince said they would not comment on private conversations, but added “we would like to stress that the Prince of Wales would not seek to make a public political statement during a private conversation."
Following the Sochi Olympics, Russia sent troops into Crimea, which later voted to rejoin the Russian Federation. Now, they are attempting to do the same in Eastern Ukraine, though they have been met with resistance from the rebel forces who deposed the Russian-backed president earlier this year.
Charles will come face-to-face with the Russian leader in a few weeks at the 70th anniversary of the D-Day landings in Normandy early next month.
"If Prince Charles wants to make controversial statements on national or international issues he should abdicate and stand for election,” Labour MP Mike Gapes tweeted. "In constitutional monarchy policy and diplomacy should be conducted by parliament and government. Monarchy should be seen and not heard."