Prince Harry, Duke of Sussex, made an unexpected appearance at a UK court on Monday during a high-profile privacy lawsuit against the publisher of the Daily Mail.
Other big names in entertainment and pop culture were also at the Royal Courts of Justice in London as proceedings in the case against Associated Newspapers proceeded.
The BBC reported that Sir Elton John and his husband David Furnish arrived around noon local time, along with actress Sadie Frost and Elizabeth Hurley.
The case alleges that unlawful practices were used to get information for stories by the publisher.
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Prince Harry alleges that he lost friends, citing "paranoia" over the "unlawful" stories that ANL newspapers published.
He claims the paper tapped phones and "largely deprived" him of portions of his teenage years.
While promoting his book "Spare," Prince Harry said he has made reforming the press in Britain his life's work. He said the lawsuits are a campaign for "accountability."
Associated Newspapers denies any unlawful behavior. The case centers around allegations of hacking, bugging and a technique known as "blagging," which is obtaining information based off deception or persuasion by impersonation.
The lawsuit claims the publisher of the Daily Mail committed unlawful acts to gather information techniques over the course of years.