Princess Eugenie has revealed the candid photo of her father that landed her in hot water.

The youngest daughter of the Duke and Duchess of York shared a picture of Andrew inside Buckingham Palace in June after the Trooping the Colour ceremony.

But the seemingly innocent snap revealed to her 288,000 Instagram followers a part of the palace normally closed off to the public — and subsequently earned her a telling-off, the Daily Mail reports.

Speaking to British Vogue, Eugenie explained: "I recently got in trouble for posting a picture of Papa in a corridor of the palace that was off-limits to the public."

Eugenie, 28, was explaining her dilemma over choosing a photo to mark Father's Day — fearing a Balmoral snap would be "too personal" and an Ascot photo "too formal".

In the offending photo, Andrew, 58, looked smart in his regimental uniform following his debut as Colonel of the Grenadier Guards.

Princess Eugenie got in 'trouble' after posting this photo to Instagram. Photo / Instagram - Princess Eugenie

The corridor, lined with marble busts and a plush red carpet, was hung with paintings including one depicting the wedding of Princess Maud of Wales, a granddaughter of Queen Victoria.

It was just one of a series of fascinating revelations from Eugenie and older sister Beatrice in their first ever joint interview, for the fashion bible's September issue.

During the accompanying photo shoot, at their Windsor home, Royal Lodge, the siblings posed in couture clothing from designers including Valentino, Erdem and Simone Rocha.

But disaster struck when one of the family's five Norfolk terriers "relieved" itself on Beatrice's foil cape from British designer Richard Quinn.

And according to Vogue's fashion features editor Ellie Pithers, the team got an unexpected visitor in the form of Sarah Ferguson, who shares a home with her ex-husband and daughters, and had just jetted in from a trip to Sardinia.

"You look beautiful! Great hair. Let's make those eyes pop," Fergie is quoted as saying, before declaring herself a "Pony Club mother".

The two sisters — who call their mother "Mumsy" — also touched on everything from life in the spotlight to fashion, social media and Eugenie's upcoming wedding in the interview.

At one point, they discussed living in the public eye as they say they constantly face "mockery" and criticism.

Of doing media interviews, Beatrice, 29, said: "It's hard to navigate situations like these because there is no precedent, there is no protocol.

"We are the first: we are young women trying to build careers and have personal lives, and we're also princesses, and doing all of this in the public eye."

Eugenie, who will tie the knot with Jack Brooksbank in October, added: "We want to show people who we are as working, young, royal women, but also not to be afraid of putting ourselves out there."

"Nowadays it's so easy to recoil when you see a perfect image on Instagram — but it's important that it's real. We're real."