Prince Harry made an unexpected appearance at London's High Court on Monday for a privacy case against a newspaper publisher.

The British royal, who is based in California, surprised awaiting press when he showed up outside the courts for a hearing into his claim against Associated Newspapers Limited (ANL), the publishers of the Daily Mail and Mail on Sunday, over allegations of unlawful information gathering.

According to BBC News, the Duke of Sussex sat towards the back of the courtroom and occasionally took notes in a small black book as ANL's legal team presented its arguments.

Sir Elton John and actress Sadie Frost, who are also involved in the legal proceedings, attended the first day of the preliminary hearing on Monday too.

Other high-profile individuals taking part in the legal action include Elizabeth Hurley, John's husband David Furnish and Baroness Doreen Lawrence, the mother of murdered teenager Stephen Lawrence.

The group launched the legal action in October 2022 after allegedly becoming aware of "compelling and highly distressing evidence that they have been the victims of abhorrent criminal activity and gross breaches of privacy" by ANL.

According to law firm Hamlins, which represents Harry and Frost, ANL allegedly hired private investigators to place listening devices in their homes and cars, recruited people to listen into phone calls, paid police officials for information, obtained medical records via deception and accessed financial records and bank accounts through illicit means.

In a statement at the time, ANL representatives said, "We utterly and unambiguously refute these preposterous smears which appear to be nothing more than a pre-planned and orchestrated attempt to drag the Mail titles into the phone hacking scandal concerning articles up to 30 years old."

The four-day High Court hearing will determine if the case should go to trial.

The royal's appearance is believed to be his first time in the U.K. since his grandmother, Queen Elizabeth II's, funeral in September.

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