Queen Elizabeth II ‘was battling cancer’ in the last few months of her life, a new biography has claimed.

Gyles Brandreth, a friend of Prince Philip, made the claims about the late monarch in an upcoming biography called ‘Elizabeth: An Intimate Portrait’.

The official cause of Queen Elizabeth II was listed as “old age”, but Gyles Brandreth claimed it was actually a rare form of bone marrow cancer that took the Queen Elizbaeth II’s life, Hindustan Times reported.

Currently, there is no known cure, but treatment — including medicines to help regulate the immune system and drugs that help prevent the weakening of the bones — can reduce the severity of its symptoms and extend the patient’s survival by months or two to three years,” the book claimed.

The book also claims the Queen suffered periods of low energy, despite telling aides she was determined to stay busy after her husband Philip’s death in April last year.