Kate Middleton unveiled her growing baby bump in a bikini, though involuntarily while on a vacation.

Middleton and Prince William were on a vacation on one of the world's most private islands, but the royal couple yet again became the victims of paparazzi.

The pregnant Duchess was snapped walking on the beach on the island of Mustique in a skimpy bikini, revealing her visible baby bump, according to the Sunday People, which decided not to publish the photos. Kate's sister Pippa too is seen in a bikini.

The photos of bikini-clad Middleton and baby bump may be a taboo for British media outlets, but they are likely to cause a bidding war in the U.S., Australia and Europe, where they "could fetch more than £250,000 ($392,000) if touted around the world," as the report states.

“This is unfortunate. They get absolutely no privacy whatsoever,” a royal source told the Sunday People.  

The news of Kate's bikini photos comes just half a year after the media frenzy over her naked photo scandal at a Chateau in France.

For the 31-year-old royal fashion icon, it seems there is nowhere on earth that gives her absolute privacy.

"William and Kate have been sunning themselves on the exclusive island of Mustique, in a secluded villa, which costs a whopping £19,000-a-week to rent," Marie Claire said of Kate and William's romantic babymoon. That is a whopping $29,000.

The royal duo's posh holiday pad sports Balinese-style antiques and artwork, and is surrounded by a serene pond, lush green gardens, a 64-foot infinity pool, a swanky sun deck and games room, reports claim.

Even as the world is more than eager to see the pregnant Duchess' growing belly, MIddleton is set to visit Hope House, Action on Addiction in London on Feb. 19, which will mark the second public appearance after her pregnancy announcement.

Just a couple of weeks ago, however, Kate's royal baby bump was snapped while she stepped out for shopping in West London.

"Kate's been laying low. She's been staying at Kensington Palace and living the life of a duchess," a royal insider told E! News.

Regardless of her efforts to keep low profile, the royal princess is likely to suffer some more of paparazzi's intrusion.