Private moments from the couple's jaunt in Seychelles' luxurious North Island last May are splashed throughout the pages of Woman's Day, an Australian tabloid, and spreading like wildfire on the internet.
For the palace, it's a symbol of broken trust, and a media betrayal that resonates in the royal family's tragic history.
But for one anonymous photographer staked out during their May escape, it could have meant a major payday.
"Any shot of them on their honeymoon was going to go for at least half a million but because Kate is in a bikini I would estimate that this is a million dollar shot," celebrity business journalist Jo Piazza, tells Yahoo! Shine.
Woman's Day hasn't confirmed any details on how they obtained the photos or for how much.
According to The Daily Beast's Tom Sykes, suspicion has turned to UK tabloid photographers, blamed in the past for shirking off privacy requests for a high-profile story.
As to the delay in releasing the photos, Sykes speculates: "whoever secretly commissioned the photos then had second thoughts about alienating the Palace, and the photographer was then forced to wait out an exclusivity period before selling them."
The delay hasn't softened the blow for the royal couple, who are reportedly distraught over the publication.
'The Duke and Duchess of Cambridge's honeymoon was obviously a private occasion, and we would ask people to respect their privacy," a St. James Palace rep told CelebBuzz.
Painstaking efforts went into preserving the newlyweds' privacy in the weeks after their internationally scrutinized wedding.
Not even Kate knew their honeymoon destination until the last minute, according to Marie Claire. Despite all that, the location of their beachside retreat in Seychelles North Island was promptly discovered by international press. Out of respect for the couple, and Prince William's late mother, the media largely promised to respect the couple's wishes for privacy with a "blackout" during their 10-day jaunt.
Coast guard patrols and security surrounding their $5000 a night bungalow provided extra protection from prying eyes.
But newly published grainy paparazzi photos, of Middleton in a black, skimpy bikini walking hand-in-hand with her shirtless husband on the beach, proved otherwise.
The image on the magazine's cover of the Aussie magazine shows a blissed-out couple, holding snorkeling gear, clueless to any member of the press hidden nearby.
15 additional images of Kate and Will swimming and relaxing fill the pages inside the issue.
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Paparazzi hiding out in dunes with long lens-equipped cameras are commonplace for high-profile celebrities on vacation, but because of scrutiny over the media's role in Lady Di's tragic death, Kate and Will have been granted more privacy.
But not everyone is surprised by the photos. "Someone was going to break it," says Piazza, author of author of Celebrity Inc.: How Celebrities Make Money. "Media blackouts rarely work. It was just a matter of who had the most financial incentive."
But is a money shot worth a breach of trust with the royal family?
"Obviously Woman's Day thought it would pay off," says Piazza, "and frankly I think that it will."