Nelson Silva, 40, said he saw a “relaxed” princess with his “own eyes” as she shopped with William in the meat section of the upmarket grocery on the Windsor Park estate on Saturday.

Health regulators stressed the importance of the confidentiality of patient information amid allegations of a medical record breach at The London Clinic when the Princess of Wales was a patient.

A spokesperson for the General Medical Council, which regulates doctors, said: “Patients must have confidence that their personal information is protected at all times.

“Our guidance is clear: we expect doctors to make sure any personal information about patients is effectively protected at all times against improper access, disclosure or loss, and they must not access a patient’s personal information unless they have a legitimate reason to view it.

“We have a duty to consider whether any concerns raised with us about a doctor’s fitness to practise meet the threshold for investigation.

“We will take appropriate action where those concerns pose a risk to patients or public confidence in the profession.”

Lesley Maslen, executive director of professional regulation at the Nursing and Midwifery Council (NMC), said: “Our code is clear that all nurses, midwives and nursing associates must respect people’s right to privacy and confidentiality.

“This includes taking all steps to make sure that people’s records are kept securely and information about them is shared appropriately.

“Whenever concerns are raised with us about professionals on our register, we consider whether we may need to take action to protect the public and to maintain trust in our professions.”

With the memory of their mother still casting a long shadow, both Harry and William are determined to do things their own way.

But, asks Tessa Dunlop, after a week of turmoil and many questions left unanswered, does this spell trouble in a world where there are now more palaces than major royal players?

TMZ, the USA’s behemoth showbiz site, insisted the palace has “got caught in a lie … confidence is shot”. Time magazine ran a similar editorial: “The royal family has a trust problem.” Both have a point, but Kensington Palace doesn’t see it like that. And nor do Britain’s supposedly attack-dog tabloids.

The hospital at the centre of claims staff attempted to access the Princess of Wales’s private medical records has vowed “all appropriate investigatory, regulatory and disciplinary steps will be taken”.

Chief executive of the London Clinic, Al Russell, said: “There is no place at our hospital for those who intentionally breach the trust of any of our patients or colleagues.”

The UK’s privacy watchdog, the Information Commissioner’s Office (ICO), is looking into the alleged royal data breach at the private hospital where Kate had abdominal surgery and is in the process of assessing the information.

Downing Street said people should “get behind the Princess of Wales”.

Asked about the alleged breaches at the London Clinic following Kate’s treatment, the Prime Minister’s official spokesman said: “Clearly there are strict rules on patient data that must be followed.”

Asked whether people should give Kate a break, the spokesman said: “I think we all want to get behind the Princess of Wales, and indeed the Prince of Wales, and we obviously wish her the speediest of recoveries.”

The chief executive of the London Clinic, where the Princess of Wales was treated earlier this year, has said “all appropriate investigatory, regulatory and disciplinary steps will be taken” when looking at alleged data breaches.

Responding to allegations that at least one member of staff tried to access Kate’s notes while she was a patient at the hospital in January, Al Russell said: “Everyone at the London Clinic is acutely aware of our individual, professional, ethical and legal duties with regards to patient confidentiality.

“We take enormous pride in the outstanding care and discretion we aim to deliver for all our patients that put their trust in us every day.

“We have systems in place to monitor management of patient information and, in the case of any breach, all appropriate investigatory, regulatory and disciplinary steps will be taken.

“There is no place at our hospital for those who intentionally breach the trust of any of our patients or colleagues.”

A BBC journalist has weighed in on the growing speculation that the woman videoed shopping with Prince William is not the Princess of Wales.

Sports presenter Sonja McLaughlan commented on a video that compares the woman in the latest footage with pictures of Kate.

In a post on X seen byThe Telegraph, Ms McLaughlan wrote: “It’s so obviously not Kate.

“Some newspapers are reporting it as fact. But it’s not her. No conspiracy theorist but all very odd.”

The footage in question was published by The Sun and appears to show the princess smiling as she walked alongside her husband outside Windsor Farm Shop, which is a short drive from their home in the grounds of Windsor Castle.

A Metropolitan Police spokesperson told The Independent the force is not aware of any referral at this time, following reports of the alleged breach at The London Clinic.

Although it is a criminal offence under the Data Protection Act 2018 to unlawfully access personal data without consent, prosecutions are usually brought by the Information Commissioner’s Office. The offence is punishable by way of an unlimited fine.

The ICO has confirmed it has received a breach report and is assessing the information.

Section 170 of the Act criminalises “knowingly or recklessly obtaining, disclosing or procuring personal data without the consent of the data controller, and the sale or offering for sale of that data”.

According to the CPS website, the law is most commonly used to prosecute those who access healthcare and financial records without a legitimate reason.

Health minister Maria Caulfield said it would be “very disappointing” if the Princess of Wales’s notes had been accessed.

She told Sky News that it is “pretty serious stuff to be accessing notes that you don’t have permission to”.

She said: “Just to reassure your viewers, these rules apply to all patients, so there are very strict rules about which patient notes you can access.

“You’re only allowed to access the patient notes you’re caring for, and with their permission, and there’s really strict rules.

“The Information Commissioner would take enforcement action against trusts or primary care practices, but also, as individual practitioners, your regulatory body… would take action as well.

“So it’s pretty severe, and it’s pretty serious stuff to be accessing notes that you don’t have permission to.”

Ms Caulfield added: “From a health perspective, it’s not acceptable to be looking at people’s notes, but it has been spotted and action has been taken so people can be reassured that if it does happen – particularly with electronic notes these days, it’s spotted pretty quickly if someone’s accessing notes that they shouldn’t be.”

The UK privacy and data protection watchdog said it had received a breach report.