German royal warns Prince Harry to be 'more careful' after 'embarrassing' King and Queen

Prince Alexander Schaumburg-Lippe warned Harry, 39, to show "more caution" after he posed with his distant relative at the awards bash.

Prince Harry beamed as he posed with Mario-Max Schaumburg-Lippe at the black tie event hosted at the Beverly Hills Hilton in LA on Friday night.

However, the German has since been branded a "fake prince".

Prince Alexander said: "I hope [Harry] will be more careful in the future and also always keep in mind the dignity of their majesties the King and Queen."

Mario-Max became known after appearing on Germany's Big Brother and several reality shows in the US.

Prince Alexander continued to tell The Mail: "If Prince Harry read about these things he may exercise more caution in the future, which would be a wise thing to do.

"In his position, you can't surround yourself with people without vetting them first."

Mario-Max was adopted at the age of 24 by a member of the Schaumburg-Lippe family and subsequently took on the title of prince.

However, Prince Alexander has asserted that Mario-Max is not a prince and has been "harvesting our name" for fame.

Mario-Max later shared his birth certificate on social media after his family questioned his right to use the title of prince.

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Writing in German and English, he said he is "Prince Waldemar, son of Princess Feodora of Denmark, and Princess Antonia Schaumburg-Lippe".

His social media supporters supported him, with one posting on X: "You are a gentleman, sir. Ignore these people. They have no honour."

During the glitzy ceremony in LA, the duke also posed with John Travolta, Jeff Bezos and the latter's fiancée Lauren Sanchez.