Pictures showing Prince Harry and a young woman naked in a Las Vegas hotel room have been published on a US website.
The two photos of the 27-year-old royal, on gossip website TMZ, were taken on a private break with friends over the weekend.
The site reported that the prince was in a group playing "strip billiards".
St James's Palace has confirmed the prince is in the photos but has made no further comment about the images.
The two pictures of the prince are thought to have been taken on Friday.
The website claims the pictures came after the prince, who is third in line to the throne, invited friends back to his hotel room for a private party.
It is not clear how the photos were taken, but it is presumed they were captured on a camera phone.
The pictures have since been picked up by much of the American media, but as yet have not been printed by any British newspaper.
The father of one of Prince Harry's closest friends told the BBC's The World at One the prince was "a very easy target" for the press.
Alex van Straubenzee, whose son Thomas has known the prince since childhood, said that "more than anything [Harry] is a British soldier".
"He has a very, very good qualification in the job he does for the Army and I think this is what people will look at," he said.
The emergence of the pictures is the latest colourful incident in Prince Harry's life.
In 2005, there was widespread outrage when an image of the prince attending a friend's fancy dress birthday dressed as a Nazi emerged.
And in 2009, Prince Harry was forced to apologise for using offensive language to describe an Asian member of his army platoon after video footage emerged.