Queen Elizabeth II once removed the royal title of her go-to luxury underwear firm due to a shocking reason, a documentary revealed.

London-based Rigby & Peller previously held an official royal warrant for 57 years and had been fitting lingerie and underwear for many female royals, including the Queen Mother, Queen Elizabeth II, Princess Margaret and Princess Diana since 1960.

“Even royals change shape over time so their undergarments measurements change shape as well," Paul Burrell, Princess Diana's former butler, explained in the 2019 Channel 5 documentary “By Royal Appointment: Shops Serving The Queen.” “So someone comes from Rigby & Peller and measures Her Majesty’s requirements to provide the most excellent undergarments.”

However, the Queen removed their royal warrant and all the privileges that came with it in 2017 after their former owner, June Kenton, released an autobiography wherein she reveals private details about the Queen. In her book "Storm in a D-Cup," Keaton, who fitted bras for the monarch during the '70s and '80s, dished about her role as the official “corsetiere” to the Queen and her visits to Buckingham Palace.

In 2018, Kenton opened up about her book and the trouble it caused her in an interview with BBC. She revealed that she had "proudly" said she went to the palace in the book, but she was later devastated when she found out what her book had cost her.

“I'm very sad Buckingham Palace took exception to the story—it's a kind and gentle story about what went on in my life," she said.

"I only ever said I went there, not what happened. I have never, ever spoken about what I do there with her, or the Queen Mother or Princess Margaret," Kenton continued. "I think it's unbelievable. It's just upsetting at the end of my life, but what can I do. I can't fight with Buckingham Palace and I wouldn't want to, but it's hard."

Queen Elizabeth II
Queen Elizabeth II is seen at the Chichester Theatre while visiting West Sussex on Nov. 30, 2017, in Chichester, United Kingdom. Getty Images/Stuart C. Wilson

Royal warrants are given to companies or crafters that provide goods and services to the royal family. At the moment, only three members of the British royal family can grant royal warrants, and these are Queen Elizabeth II, her husband Prince Philip and son Prince Charles.

Any company is allowed to apply for a royal warrant, but they can only be eligible for the honor if they have been supplying goods to the household of one of the three royal family members who could grant them for five years or more out of seven.

Burrell, however, said that it wasn't necessarily because Kenton revealed details about the Queen's intimate measurements that her company was stripped of its royal warrant. Just the fact that she said she talked about private information related to the monarch had apparrently been reason enough for the Queen to remove Rigby & Peller's title.

"That was enough to be repelled from the royal presence," the former butler explained.

Despite losing its most famous client, Rigby & Peller still serves some notable celebrities, including Kim Kardashian, Joan Collins and Gwyneth Paltrow.