Britain's Queen Elizabeth has sparked fears for her health after cutting back her royal duties.
The 87-year-old royal is believed to be frailer than palace aides are letting on, according to the Daily Star Sunday newspaper.
An insider said: "Whenever they ask what is happening, the Royal Household staff just say it's a private matter for the Queen and her doctors.
"But it's important as they need to know - we are talking about the head of state.
"The Royal Family are concerned and so are the security services."
Royal engagements monitor Tim O'Donovan has confirmed Queen Elizabeth has cut down on her public appearances.
Figures show during last year's Jubilee celebrations she had 425 in her diary and this year she has completed 341 so far, which is down from 370 in 2012.
Her Majesty was struck down by gastroenteritis in March and was hospitalised for the first time in a decade.
Last month she decided not to go to Sri Lanka for the Commonwealth Heads of Government Conference and Prince William, 31, has given up his military career to help out with more official duties.
Royal watcher Mr O'Donovan said she is right to be cutting back her royal appearances.
He said: "This year she is doing less and cutting down on investitures that are quite tiring. She has Prince Charles, the Princess Royal and the Duke of Cambridge helping."
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