Patient safety at a private hospital which is favoured by the Royal Family must be improved, health inspectors have said.
Aspects of safety, medical care, surgery and work in the outpatient department at the King Edward VII's Hospital "require improvement", according to the Care Quality Commission (CQC) which carried an inspection over three days in January and February.
It stated it had "concerns that senior leaders did not have an adequate management strategy on incident investigations" and had spotted 671 incomplete incidents.
They said there was "a lack of oversight" of consultants' practising privileges.
The inspectors told the hospital provider it "must take some actions" to comply with the regulations and it "should" make other improvements.
It also issued two requirement notices.
The central London hospital in Marylebone, which counts the Queen as its patron, is the private hospital of choice for senior members of the Royal Family when they are advised to have an overnight stay.
The Duke of Edinburgh, the Duchess of Cambridge during her pregnancy with Prince George, the Prince of Wales and the late queen mother have all been patients.
In a statement, a spokesman said the hospital was "extremely disappointed" by the rating and said it places "the delivery of the highest standards of medical and nursing care to patients as our priority".
The CQC report states: "We found that within (the) recovery unit the medicines cabinet was regularly kept unlocked, the risk of 'poor medicines management, theft, fraud or harm especially in relation to management of controlled drugs' was on the departmental risk register."
The inspectors found the number of patient falls were "high" when compared to other similar services but said the hospital explained it routinely reported all types of fall, including near miss and low harm falls.
It noted the outpatient department did not maintain complete patient records.
Work in surgery, medical care and the outpatients' department was found to be "good for caring and responsive" but could be improved.
The inspectors also said there a "positive culture" at the hospital and staff spoke positively about the leadership team.
The Duchess of Cambridge was taken to King Edward VII's Hospital with a rare form of morning sickness during the early stages of her first pregnancy.
It was the workplace of Jacintha Saldanha, the nurse who took her own life after answering a phone call from two Australian DJs imitating the Queen and the Prince of Wales.
The Duke of Edinburgh, then 90, was admitted for five days after suffering a bladder infection after enduring a wet and windy trip down the Thames during the Diamond Jubilee River Pageant.
Other members of the royal family who have been treated there include the late queen mother, admitted to have a fish bone removed from her throat in November 1982, the Prince of Wales, who had a routine hernia operation in 2003, and the Duchess of Cornwall for a hysterectomy.
A hospital spokesman said: "We were pleased to note the Commission's positive review of our work as caring, effective and responsive.
"We note, however, that the Commission has identified a number of governance processes that, in their judgment, fell short of their requirements.
"We have already addressed many of these areas, and everyone at the hospital is fully engaged in a rigorous action plan to further improve the processes which were identified.
"Nothing is more important to us than ensuring that our patients receive the best care at all times.
"We look forward to welcoming the CQC back in due course to review progress."