Up to three people could be involved in the alleged accessing of Kate’s medical records, it’s been claimed.

Sources said three staff at the London Clinic are being investigated, according to The Mirror.

The three could face disciplinary action for a potential breach of data.

Scotland Yard could be called in to investigate the reported action at the clinic in Marylebone, the paper said.

Health minister Maria Caulfield has already said police have been asked to look into the case.

The editor-in-chief of Majesty magazine has said the online rumours and frenzy around Kate were “spiralling out of control”.

Ingrid Seward said she had a “chilling feeling” that reminded her of the time just before the death of Diana, Princess of Wales.

Ms Seward told Times Radio: “For me, it sort of has a very chilling feeling.

“It reminds me that just before the Princess of Wales was – the other, you know, Diana, Princess of Wales – was tragically killed in that car accident, it was spiralling out of control then.

“I remember every single day it was headline news – what she was doing on her holiday in France with Dodi Fayed.

“I just remember saying, ‘this is spiralling out of control’. And I’ve got the same feeling now.”

She said the royal family was entitled to privacy.

But Ms Seward warned that the Windsors needed a new strategy, and suggested the late Queen’s advice to ignore rumours belonged to a different era.

“I think it is a world that’s gone. As much as it did used to work. ‘Never complain, never explain’ did work, but it doesn’t work now, not in the age of social media,” she said.

The Queen has arrived in Northern Ireland at the start of a two-day visit.

Camilla was greeted by staff at Hillsborough Castle in Belfast as she arrived at the royal residence on Wednesday evening.

She will undertake a series of engagements on Thursday.

Data-protection watchdog the Information Commissioner’s Office has put out questions and answers in view of the investigation over accessing the Princess of Wales’ medical records. It warns it could be a criminal offence, saying:

Should I be worried about someone looking at my medical records? Organisations have a responsibility to look after your personal information carefully. That means keeping it secure, and making sure it can only be seen by people who need to use it. If organisations do not keep your personal information safe in line with the law, the Information Commissioner’s Office (ICO) can step in. What can the ICO do? An organisation must report misuse of personal data to the ICO if there is a risk to people’s rights and freedoms, which is often the case with sensitive medical information. This must be reported within 72 hours of becoming aware of the breach.

What happens next? Accessing someone’s medical records without cause or consent can be a criminal offence. If the ICO investigates and finds evidence that medical records were accessed illegally, it can take action. This can include prosecuting and fining the person responsible in court. For example, last year the ICO prosecuted a medical secretary who accessed over 150 people’s records. She was fined by the courts. The ICO can also take action against organisations, including fines, if an investigation finds they did not do enough to protect people’s personal information. For example, last year the ICO reprimanded an NHS Trust after it allowed a member of the public to read patient’s medical records.

William was on official duties today amid speculation about Kate’s health.

The Prince of Wales, Colonel of the Welsh Guards, met military personnel from the 1st Battalion Welsh Guards during a visit to Combermere Barracks in Windsor, Berkshire.

Kate was admitted to hospital a week after her 42nd birthday:

Police have been asked to look into the alleged attempt to look at the princess’s records, health minister Maria Caulfield said.

“Whether they take action is a matter for them,” she told LBC radio.

“But the Information Commissioner can also take prosecutions,” she added.

Earlier on Wednesday, a Metropolitan Police spokesperson told The Independent the force was not aware of any referral.

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.”