Prince Harry Vegas Pictures

Prince Harry's underwear from his infamous strip billiards game in Sin City is hitting the open market ... a former stripper says she kept the undies for a decade and is now ready to sell.

The 10-year anniversary of Harry's wild night in Vegas is coming up this month, and ex-stripper Carrie Royale feels the timing is right to sell the Prince's royal undies from that fateful night in a high roller's suite.

The exotic dancer claims she was in the hotel room with Harry when he stripped down to his birthday suit playing pool ... and she's also auctioning off the dress and swimsuit she says she wore that same night.

What's a royal family keepsake like this worth? The stripper believes the winning bid could reach as high as $1 million.

The photo was snapped in Vegas back in August 2012, with Harry cupping his genitals with a seemingly topless woman and bear-hugging another woman who appeared to be nude as well.

Carrie Royale says word on the street is Prince Harry dropped by Larry Flynt's Hustler Club during his wild trip to Vegas, so the strip club is hosting the auction.

The stripper believes the underwear sale is a full circle moment for Prince Harry, saying ... "I am holding the auction to help remind him of his fun side, the side that his marriage to his wife Meghan has tried to control." Wow.

The live and online bidding starts Thursday at 10:30 PM PT, with a starting bid of $10,000. If the bidding reaches $800k, the winner gets a vintage 3-liter bottle of 1996 Dom Pérignon Rose wrapped in 24 karat gold, valued at over $200k.

It's a stripped down battle of the buns!

Here's Justin Bieber (19) live and unclothed during a Thanksgiving serenade to his grandma (left) ... and Harry the Prince of Wales (28) wearing nothing but the family jewels during a naked billiards party in Vegas (right).

The Mayor of Las Vegas is making a serious plea to Prince Harry now that he's back from Afghanistan -- COME BACK TO VEGAS, ASAP!!!

Harry completed his 5-month military stint in the Middle East this week ... and once he got out of the war zone, he finally broke his silence about his Sin City naked photo scandal to the U.K. media ... saying, "I probably let myself down."

But TMZ spoke with Mayor Carolyn G. Goodman ... who thinks Harry deserves a Vegas do-over ... and tells us the city is ready to roll out the red carpet for His Royal Highness when he's ready to come back.

"We’re absolutely excited he’s home," Goodman says ... adding, "Prince Harry is always welcome in Las Vegas. When he was here everyone was talking about it. We welcome him back with open arms.”

It's no surprise ... considering the city reportedly enjoyed $23 million in free publicity that was generated by the naked billiards scandal.

It took 5 months, but Prince Harry is finally talking about his infamous game of strip billiards during his Las Vegas party weekend ... telling the media, "I probably let myself down."

Harry spoke with U.K. reporters after completing a 5-month military stint in Afghanistan -- and that's when someone asked about the pics ... first published on TMZ.com.

"I probably let myself down," Harry said ... adding, "I let my family down, I let other people down."

He continued ... "At the end of the day, I was in a private area and there should be a certain amount of privacy ... The way I was treated ... I don't think is acceptable."

"Back home all my close friends rallied round me and were great."

Harry said he considers the incident a "classic example of me probably being too much army and not enough prince".

We broke the story ... Harry had invited a bunch of random women he met at a hotel bar up to his VIP suite for a party back in August ... and during the shindig he stripped down to his birthday suit after losing a game of strip billiards.

Prince Harry's penis is being hailed as a HERO by Vegas officials ... 'cause experts say the free worldwide publicity Sin City enjoyed from the naked billiards scandal is worth roughly $23 MILLION.

The Las Vegas Convention and Visitors Authority issued a report, in which it says the pictures of Harry romping around his hotel room with a hot naked lady has reached an estimated 154 MILLION PEOPLE worldwide since TMZ broke the story back in August.

The agency says it's unable to track how much tourism has been generated due to the publicity ... but LVCVA Board Chairman Tom Collins is clearly optimistic ... saying at a recent board meeting, "God bless Prince Harry. He made us a bunch of money."

FYI -- The LVCVA had launched an advertising campaign for the city earlier in the summer warning tourists to "know the code" ... what happens in Vegas stays in Vegas.

When someone broke the code and shared the pics of the naked Prince, some officials felt the timing couldn't have been better.

The Royals apparently believe Prince Harry has a place in The Sun, because they've decided not to take legal action against the U.K. tabloid for publishing Harry's naked pics.

The Royals have concluded, "We remain of the opinion that a hotel room is a private space where its occupants would have a reasonable expectation of privacy. Prince Harry is currently focused entirely on his deployment in Afghanistan, so to pursue a complaint relating to his private life would not be appropriate at this time and would prove to be a distraction."

Kate Middleton's second cousin once (clothing) removed Katrina Darling is following in Prince Harry's X-rated footsteps and getting naked for the camera too.

Katrina -- who as of earlier this year hadn't ever met the Duchess of Cambridge -- was barely dressed as the Statue of Liberty and once again brought her risque burlesque performance to a NYC club on Wednesday.

Spotted: A bunch of Prince Harry wannabes in cheap paper masks

Location: Encore Beach Club in Vegas ... the same hotel where the REAL Prince Harry got naked with a bunch of chicks last month.

Going out in public for the first time since TMZ published nude photos of him in Las Vegas, a clothed Prince Harry showed up today to the WellChild Awards ... which are being held at the InterContinental Hotel in London.

The event is held annually and honors the lives of the young people and the doctors and nurses who care for them.

As TMZ first reported, Prince Harry vowed he would appear at some point during this week's 2012 Paralympic Games in London, though it was unclear which event he would show up to first.

Prince Harry is adamant ... he WILL attend the 2012 Paralympic Games in London ... refusing to back out of his first scheduled appearance following the naked photo scandal.

Harry has been M.I.A. since returning to London from his X-rated Vegas weekend ... and there were rumors he would be cancelling all of his appearances and staying out of the spotlight until the whole thing blows over.

But TMZ spoke with a rep for the Royal Family who tells us ... "The Duke and Duchess [of Cambridge] and Prince Harry will attend select events during the Games, including goalball, cycling, swimming and Athletics.”

The Games are scheduled to begin tomorrow and will run through September 9. The rep was not clear about when Harry will show up.

Stay tuned ...

People around the world are coming together to show their support by Prince Harry ... in the form of naked tributes on Facebook.

TMZ has discovered ... a Facebook group called , "Support Prince Harry with a Naked Salute" has popped up online ... with marching orders to back the Prince, by showing your front.

The rules are simple, "please cover your crown jewels, tag yourself in your photo as proof of your support to the nations favourite Royal!"

Supporters are firing in their pics in droves .... both men and women.

Rupert Murdoch's got Prince Harry's naked back ... telling the world to give the young royal a break over his recent Vegas scandal -- not surprising, since Murdoch defied the Royals by publishing the pics.

Murdoch tweeted Saturday night, "Prince Harry. Give him a break. He may be on the public payroll one way or another, but the public loves him, even to enjoy Las Vegas."

TMZ broke the story ... the prince was photographed bare-ass playing billiards in Las Vegas this week and the photos quickly made the rounds all over the world. But the Royal Family was none too happy and pressured/banned British media outlet from publishing the pics.

Enter "The Sun" -- one of Murdoch's many media companies -- which published the nudie pics anyways.

Well played.

You might have heard we posted a few pics of Prince Harry the other day which kinda made the rounds. So we gotta ask ...

You knew it was coming ... and now, so does Prince Harry -- a multi-million dollar offer to get down and dirty in a XXX movie ... courtesy of the biggest porn studio on the planet.

Vivid Entertainment honcho Steve Hirsch just fired off a letter to the royal palace in London -- offering Prince Harry $10 million to star in a big budget adult film called "The Trouble with Harry" ... thanks to his recent naked romp in Vegas.

According to the letter, the film would also star "little Harry" and would feature some REAL royal carousing -- in the form of full-on boning.

Hirsch writes, "We assure you the sex will be well-scripted, and the crown jewels will not be 'minimized' in any way."

Prince Harry realized he made a huge mistake by allowing girls with cameras into his Vegas hotel room Friday night -- because just two days later in Sin City ... he was INCREDIBLY camera shy, refusing to pose for any pics with fans.

TMZ spoke with one of the girls Harry was hanging out with at a pool party Sunday night -- two days after the naked pics were taken -- and when she asked him to pose with her and her friends, Harry politely refused, saying. "No photos please."

It's a big shift in behavior from Friday -- when Harry invited several strange girls into his Vegas suite, and stripped naked in front of their cameras.

It didn't end there either, Harry happily goofed around at Wet Republic the next day -- probably the most photographed pool party in town.

But by Sunday night, Harry had grown tired of all the cameras.

As for his security ... our source says Harry was SURROUNDED -- in fact, she noticed at least 10 handlers around the pool. According to her, one of the security guards was even in the water with a waterproof cell phone (for aquatic emergencies).

But photos or no photos -- our girl says Harry was really flirty ... saying he was glad she made it to the pool party, and nodding to her bikini.