Remarks attributed to the Prince of Wales likening Vladimir Putin's actions to some of those of the Nazis are "outrageous", BBC quoted Thursday the Russian embassy as saying.
Deputy ambassador Alexander Kramarenko has met foreign office officials to ask for official clarification.
The alleged comments were made during a conversation with a former Polish war refugee during a royal tour to Canada.
A Russian foreign ministry spokesman said "the remarks did the prince no credit, if he really said this".
Kramarenko met senior Foreign Office director Sian MacLeod in Whitehall.