Our man among the crowd of 100 who were watching said: "The princes were due at any time and the police were getting pretty jittery.
"Elton pulled up in the back of a people carrier. A policeman stepped into the middle of the road to stop the car and he said to the driver, "Sorry you can't come in here at this point.
"You'll have to drive round the back or park up and wait five minutes". The driver then said, "I have an important artist in the back who needs to get to his dressing room".
"The policeman said, 'I don't care who's in the car, you cannot drive down this road right now".
"At that point, Elton wound down the window and screamed at him.
"The policeman calmly said to him, 'Sorry but you are not going in this road. You have to get out and walk from here or take a drive around the block. We're waiting for the princes, who are coming through here any minute'.
"Elton started ranting and swearing again. He just lost it and instructed his driver to drive around the policeman.
"The driver started to move and at that point, the policeman stood in front of the car gesturing to put his hands on the bonnet. The policeman was saying to the driver, 'Stop there or you'll be arrested'.
"Sir Elton wound his window back up as he realised photographers were starting to congregate.
"His security guard started reasoning with the policeman, saying they needed to get him in there right away but the policeman would not budge.
"Then at that point, Elton jumps out of the back of the car, stomps round to the front and barges through to get into the backstage compound.
He stomped down the road shouting at people to 'get out of my way'."