A royal source confirmed that the two photos published on the celebrity gossip website TMZ were of Harry, who has a reputation as a partying playboy and is often linked to an array of women in Britain's tabloids.

"He's been doing a lot of good work for the queen and getting a good reputation and, though a lot of people think this is a great laugh, it brings the monarchy into disrepute and will embarrass the queen," said royal author Robert Jobson.

One snap showed Harry covering his genitals with his hands while an apparently naked woman hides behind his back.

The other pictured the naked 27-year-old prince clinging to a naked woman from behind.

"Prince Harry put the crown jewels on display in Vegas this weekend," TMZ said.

According to TMZ, Harry and his friends had invited women from the hotel bar up to their VIP suite, where they played a strip game at a pool table. It did not identify the women.

The prince, a British army Apache helicopter pilot, has been on a private holiday with friends in Las Vegas after completing his final pilot's training.

Harry, son of heir to the throne Prince Charles and his late former wife Princess Diana, earned a reputation when he was younger as a royal wild child after he admitted in 2002 to dabbling in dagga and under-age drinking. Three years later he made headlines when he wore a Nazi uniform to a costume party. In recent years he has shed much of that image.