Insisting it was a sweet story of a corsetiere, Mrs Kenton said: "I probably should have submitted it to them but I didn't think anything would be required". What is a Royal warrant?
The lingerie company is now forbidden to display the royal coat of arms and has been stripped of its royal warrant.
Kenton has told reporters she never discusses what happens in a fitting room, though the book does recount her first meeting with the monarch and her trepidation about being ushered into the royal bedroom.
Royal warrants are issued to trades people and companies who regularly supply goods or services to the monarchy with many considering it to be one of the highest business accolades in the UK. For example, Fortnum & Mason has a warrant as "Grocer & Provision Merchant" to the monarch, while Hunter & Hyland Ltd. supplies curtain rails and upholstery fittings.
What did Mrs Kenton write about?
"I've been honourable throughout my life - it's unbelievable they don't like the book, there's nothing in it that they could remotely be upset about".
The 82-year-old's autobiography was released last March and tells the story of the famous chests that she has worked with over the years.
She also revealed that Diana, Princess of Wales used to accept posters of lingerie and swim models for Prince William and Harry to put up on their walls at Eton. "That's between you and the customer".
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"Sometimes the Royal warrants are withdrawn in spectacular fashion, such as when in 2002 Prince Philip, Duke of Edinburgh demanded that his warrant for Harrods department store be removed".
Who else has lost a royal warrant?
What has Buckingham Palace said? However, officials from the Buckingham Palace refused to comment on whether this was the cause.
Buckingham Palace said: 'In respect of Royal Warrants, we never comment on individual companies'.
But Rigby & Peller confirmed the loss of the Royal warrant.
"I can confirm the warrant for Rigby & Peller is cancelled but I can't go into the details why", a spokesman for the Royal Warrant Holders Association told AFP.
"However, the company will continue to provide an exemplary and discreet service to its clients", it said.