Prince Harry, Elton John at court in privacy case

STORY: Britain's Prince Harry and singer Elton John made a surprise appearance at London's High Court on Monday as they and several others began a lawsuit against the publisher of the Daily Mail newspaper over years of alleged phone-tapping and privacy breaches.

The high-profile celebrities as well as actors Elizabeth Hurley and Sadie Frost brought a lawsuit against Associated Newspapers or ANL, alleging they were victims of "numerous unlawful acts," including hacking mobile phone messages, bugging calls and even breaking into private property.

ANL, which is seeking to have the case thrown out, said in a statement it categorically denied the allegations and would vigorously defend them if necessary.

A spokesperson for Prince Harry, who flew in from California, said he wanted to be there to show his support.

In his claim, Harry accuses ANL of seeking information about private flight details of his ex-girlfriend, Chelsy Davy, and hacked mobile phone voicemail messages and bugged the landlines of his friends.

The claim said the unlawful attempts to find out details of the royal's private travel plans were a significant security risk and "dangerous."

In court submissions, ANL said the claims were based on inference rather than evidence, and that there was little or no evidence of unlawful information gathering by its journalists – which it strongly denies.

Media intrusion was one of the reasons Harry and Meghan cited for stepping back from royal duties and moving to California to start new lives.