Former UK Prime Minister Boris Johnson has revealed that Queen Elizabeth II was diagnosed with bone cancer before her death.

​​Former U.K. Prime Minister Boris Johnson said the late Queen Elizabeth II had a form of bone cancer in her final years. Johnson’s new memoir, Unleashed, will hit booksellers’ shelves in October. But an excerpt teased this week offered a rare behind-the-scenes glimpse into the queen’s cause of death.

Royal reporter Robert Jobson disclosed details in his book, “Catherine, the Princess of Wales: A Biography of the Future Queen,” that Elizabeth II felt “terribly frail” owing to a battle with a type of bone marrow cancer known as myeloma.

Boris Johnson's decision to reveal the late monarch's diagnosis is likely to raise eyebrows at Buckingham Palace.

“I had known for a year or more that she had a form of bone cancer, and her doctors were worried that at any time she could enter a sharp decline,” Johnson wrote of his last meeting with the Queen at Balmoral on September 6 when he formally tendered his resignation.

In a chapter from his upcoming memoir Unleashed, Johnson recalls his final meeting with the monarch at Balmoral on September 6, 2022, two days before her death, claiming staffers tried to warn him her condition had deteriorated.

“I had known for a year or more that she had a form of bone cancer, and her doctors were worried that at any time she could enter a sharp decline,” Johnson wrote of his last meeting with the Queen at Balmoral on September 6 when he formally tendered his resignation.

LONDON — The late Queen Elizabeth II had a form of bone cancer in her final years, Boris Johnson claimed in his memoir.

Queen Elizabeth had a form of bone cancer, former UK Prime Minister Boris Johnson has declared in a new memoir, claiming he knew for “a year or more” before her death.

"Her doctors were worried that at any time she could enter a sharp decline," the former prime minister writes about the late Queen in his memoir 'Unleashed'