Elton John claims he once saw Queen Elizabeth slap someone

It seems impossible to believe Queen Elizabeth would ever slap someone.

But that's exactly what Elton John is claiming in his new book.

The singer has recounted an incident at a party he attended with a number of members of the royal family, including Her Majesty

He says that after ignoring her request, the Queen lashed out at a relative with a slap round the face.

So who was on the receiving end of her wrath?

Find out in the video above.