Prince Harry has drawn Prince William and Princess Kate into his ongoing legal fight against the Daily Mail’s publisher, escalating tensions within the Royal Family.

According to new details submitted to the High Court, the Duke of Sussex claims that private investigators spied on the Prince of Wales and accessed personal data linked to Kate during their younger years.

Invoices Point to Surveillance of Royals

Lawyers for Harry presented invoices allegedly showing surveillance activity around Prince William’s 21st birthday party, as well as searches connected to Catherine Middleton, Kate’s maiden name.

One 2003 invoice refers to a £350 payment for “Out of Africa Story Royal Party Enqs” tied to William’s 21st birthday celebrations. Another mentions mobile phone data belonging to Catherine Middleton, while additional records show searches linked to the Middleton family home. A separate document listed 10 numbers from a “family and friends” contact sheet, with Kate’s highlighted among them.

These documents, Harry’s team argued, were discovered within five boxes of invoices described as “highly significant” and only handed over last week. His barrister, David Sherborne, told the court that the files had not been fully reviewed but already appeared “highly relevant” to the wider case.

High Court Submissions

The latest evidence was formally submitted on Wednesday as part of Harry’s lawsuit against Associated Newspapers, which owns the Mail on Sunday and MailOnline. The publisher has rejected the allegations outright, dismissing them as “lurid” and without foundation.

Harry is one of seven public figures pursuing legal action over alleged privacy violations spanning nearly 30 years. Actress Sadie Frost and filmmaker David Furnish attended the case management hearing in person, while other claimants joined remotely.

At one moment during the hearing, Harry himself joined virtually and could be heard politely reminding Baroness Lawrence to adjust her settings: “Doreen, please mute your phone,” he said when her microphone picked up a background conversation.

Broader Implications for the Royals

The new references to Prince William and Kate are part of proposed updates to the lawsuit. Their inclusion threatens to deepen already fragile family relations, coming just weeks after Harry briefly reunited with King Charles for a private meeting at Clarence House—their first in 19 months.

Associated Newspapers is seeking to narrow the scope of the case, arguing that some elements should be struck out, including material related to Harry’s past lawsuits against other media outlets. The trial is scheduled to begin in January.