The world renowned hospital where the Princess of Wales was treated has launched an investigation over claims staff attempted to access her private medical records.

Bosses have launched a probe into the claims Kate’s confidentiality was breached while she was a patient in The London Clinic in January. At least one member of staff was said to have been caught trying to access the 42-year-old’s notes. The allegations has sent shock waves through the hospital in ­Marylebone, Central London, which has a reputation for discreetly treating of the royal family, former presidents, PMs and celebrities.

One insider revealed: “This is a major security breach and incredibly damaging for the hospital, given its unblemished reputation for treating members of the Royal Family. Senior hospital bosses contacted Kensington Palace immediately after the incident was brought to their attention and assured the palace there would be a full investigation. The whole medical staff have been left utterly shocked and distraught over the allegations and were very hurt that a trusted colleague could have possibly been responsible for such a breach of trust and ethics.”

The probe comes after video and pictures emerged this week of Kate and Prince William at a farm shop in Windsor, amid conspiracy theories being churned out by internet trolls about her absence since having an abdominal operation. It is a criminal offence for any staff in an NHS or private healthcare setting to access the medical records of a patient without the consent of the organisation’s data controller. The Metropolitan Police did not confirm whether it had been informed of the allegations.

An Information Commissioner’s Office (ICO) spokesperson said: “We can confirm that we have received a breach report and are assessing the information provided.”

The London clinic refused to comment on the claims but said: “We firmly believe that all our patients, no matter their status, deserve total privacy and confidentiality regarding their medical information.” The hospital informed the Palace of the alleged breach as soon as it was discovered, sources said. Kensington Palace said: “This is a matter for The London Clinic.”

Kate is understood to have been made aware of the alleged incident. Kate, who has been recovering at home in Windsor since she was discharged from the hospital on January 29 after 13 nights there, has chosen not to reveal the reason she was admitted. Sources have said it is something she may wish to do in the future. The private 56-room hospital opened in 1932. It has treated an array of royals, including the late Queen, Prince Philip, Princess Margaret as well as late US president John F Kennedy.

Ex-PMs including Labour leader Clement Attlee and Tory ­Anthony Eden have also been patients. The King, 75, was in the hospital at the same time as Kate with an enlarged prostate. During his three-night stay, doctors found he had a “form of cancer”, for which he is now being treated. The Princess has not taken part in any official duties since Christmas Day when she went to church with the rest of the Royal Family at Sandringham, Norfolk.

Kensington Palace announced she would not return until at least after Easter, but that did not stop cruel trolls bombarding social media with theories as to why she had vanished from public life. In a bid to quell the frenzy, aides released a Mother’s Day picture of Kate with William and their children, George, Charlotte and Louis.