The Duke of Sussex filed the document as part of his ongoing legal action against Associated Newspapers Limited.

Prince Harry has named his brother Prince William and sister-in-law Princess Catherine, in a witness statement submitted to the High Court. Harry filed the document as part of his ongoing legal action against Associated Newspapers Limited (ANL), which publishes the Daily Mail and The Mail on Sunday.

Harry joins other high-profile claimants who accuse the newspaper group of unlawfully gathering private information. ANL strongly deny the accusations made against them.

The witness statement characterised Harry and William’s sibling bond. Harry wrote: “Due to his position, the press have always been very interested in him. As brothers, we naturally discussed personal aspects of our lives as we trusted each other with the highly sensitive information we shared about our private, family and professional lives.”

Prince Harry filed a witness statement as part of ongoing legal action (Image: Max Mumby/Indigo/Getty Images)

Princess Kate’s entry proved the most concise, with minimal elaboration. The statement simply noted: “HRH The Princess of Wales, my brother’s wife.”

Elsewhere, Harry mentioned his father, King Charles. He wrote: “During the Relevant Period, my father and I were in regular contact.” Harry added that voicemails left on his father’s landline phone by himself, relatives and Royal Household staff contained “highly personal, private and sensitive information.”

Despite the King returning to London yesterday to conduct engagements at Lancaster House, Harry had no arrangements to see the King during this visit, months after their reunion in London last September.

Prince Harry gave evidence at the High Court yesterday (Image: Peter Nicholls/Getty Images)

Harry, Sir Elton John and his husband David Furnish, campaigner Baroness Doreen Lawrence, former Lib Dem MP Sir Simon Hughes, and actors Sadie Frost and Liz Hurley, are all bringing legal action against ANL over allegations of unlawful information gathering.

This includes claims that information was obtained through unlawful activities such as phone hacking, “blagging” private records, and obtaining flight details.

ANL has strongly denied wrongdoing and is defending the claims.