The princess checked in to the London Clinic for “planned abdominal surgery,” according to Kensington Palace, the official London residence of Prince William and Catherine. She spent almost two weeks at the clinic in January.

Catherine is now recovering at her home in Windsor, the palace said, as questions about her health persist. Those doubts have generated a massive public frenzy, even though the palace said at the time that she was “unlikely to return to public duties until after Easter.” The issue has made global headlines, while the question “Where is Kate?” has trended consistently on social media, spawning a plethora of conspiracy theories about her health.

The exclusive London Clinic, which has also treated King Charles III as well as a number of prime ministers and celebrities, has initiated an internal investigation, according to the Mirror, a British tabloid, which first reported the story. The paper reported that at least one clinic staffer attempted to access Catherine’s medical records in breach of confidentiality.

The London Clinic declined to comment on the allegation to The Washington Post but said in a statement to the Mirror, “We firmly believe that all our patients, no matter their status, deserve total privacy and confidentiality regarding their medical information.”

Kensington Palace also declined to comment, saying that it is a matter for the London Clinic.

At the time of her surgery, the palace said the Princess of Wales appreciated the interest that her procedure would generate but that she hoped the public would “understand her desire to maintain as much normality for her children as possible; and her wish that her personal medical information remains private.”

Under British law, medical facilities are required to protect patient confidentiality, which extends even beyond death. Disclosure of any confidential patient information is only permitted for “the direct clinical care of the patient to whom it relates,” according to England’s National Health Service. Exceptions apply only when the patient explicitly consents to the disclosure, if it’s required by law, or if the disclosure can be justified in the public interest.

“We can confirm that we have received a breach report and are assessing the information provided,” a spokesperson for the Information Commissioner’s Office said, without giving further details about the nature of the breach or its assessment.

Maria Caulfield, a government minster for women’s health, underscored Wednesday the severity of any potential breach and said it was “really important that patients have confidence that only those people who are looking after them can see their medical notes.”

“These rules apply to all patients, so there are very strict rules about which patient notes you can access,” she told Sky News in an interview. “It’s pretty severe, and it’s pretty serious stuff to be accessing notes that you don’t have permission to access,” Caulfield added. “But it has been spotted, and action has been taken.”

The princess, 42, was last seen at a public engagement in December at a Christmas Day church service in Sandringham, eastern England.

Speculation grew rife after Prince William pulled out of a memorial service in Windsor on Feb. 27 at the last minute due to a “personal matter,” according to the palace. The British army added to the confusion when its official website said Catherine would attend a Trooping the Colour military parade in June — an annual event that marks the monarch’s official birthday — before removing her name hours later.

Communication blunders continued when Catherine apologized for “confusion” after editing a photo of herself and her three children that was released March 10 in celebration of Mother’s Day in Britain. The photo was retracted by global news agencies over concerns it had been doctored. The couple were seen in video footage published on the Sun newspaper’s website this week, visiting a farm shop in Windsor, which some observers speculated could quell the online rumors. Kensington Palace declined to comment on the video.

As Britain’s most scrutinized family, the country’s royals have often struggled to maintain a balance between their personal privacy and public duties.

Over the years, several intruders have penetrated the grounds of royal palaces, most notably in 1982 when Michael Fagan entered Queen Elizabeth II’s bedroom. Royals including Prince Harry and Meghan have often spoken out about privacy concerns and filed suits to protect their privacy from paparazzi and tabloids.