Duke of Sussex Claims Private Investigators Spied on Prince of Wales as New Court Documents Reveal Surveillance of Princess Kate’s Phone Data
Prince Harry has publicly dragged Princess Kate and Prince William into his explosive legal fight against the Daily Mail publisher, risking further damage to already strained royal relations as new court documents reveal alleged surveillance of the Prince and Princess of Wales.
The Duke of Sussex has claimed private investigators spied on his elder brother, with lawyers producing invoices allegedly showing surveillance around William’s 21st birthday party and phone data linked to Catherine Middleton, now the Princess of Wales, according to details submitted to the High Court on Wednesday.
The explosive filings threaten to inflame tensions within the Royal Family as Harry pursues his case against Associated Newspapers Limited (ANL), which owns the Mail on Sunday, MailOnline and the Daily Mail. The revelations come just weeks after the Duke reunited with King Charles for the first time in 19 months during a private meeting at Clarence House.
Damaging Evidence Emerges
Harry’s legal team said the material was found within five boxes of invoices described as “highly significant”, which were only handed over by the publisher last week. His barrister, David Sherborne, told the High Court that the documents had not yet been fully reviewed but appeared “highly relevant” to the wider case.
One invoice from 2003 specifically refers to a payment for information about Prince William’s Out of Africa-themed 21st birthday party at Windsor Castle, the lavish celebration that saw 300 guests arrive in exotic costumes for what was dubbed one of the most memorable royal parties in recent memory.
The invoice, linked to private investigator Christine Hart, records a payment of £350 to Hart’s company Warner, dated 25 August 2003, and is headed: “Out of Africa Story Royal Party Enqs”.
Princess Kate’s Personal Data Targeted
More troubling still are allegations that mobile phone data belonging to Catherine Middleton was targeted whilst she was dating Prince William. Separate searches were carried out on the Middleton family home, according to the court documents.
A further record listed 10 numbers from a “family and friends” list, in which Kate’s number was specifically highlighted, suggesting systematic surveillance of the future Princess of Wales’s private communications during her courtship with the heir to the throne.
The new references to Prince William and Princess Kate appear in paperwork filed for a two-day case management hearing, with the mentions of the Princess of Wales included in proposed updates to the lawsuit.
High-Stakes Legal Battle Continues
The Duke of Sussex is among seven high-profile individuals taking legal action against Associated Newspapers over alleged privacy violations spanning three decades. Other claimants include Sir Elton John, Baroness Doreen Lawrence, actress Sadie Frost, actress Elizabeth Hurley, filmmaker David Furnish, and former politician Sir Simon Hughes.
The publisher, which owns the Mail on Sunday and MailOnline, vigorously rejects the allegations and has described them as “lurid”, “preposterous smears” and unfounded.
Associated Newspapers is pushing to narrow the case, insisting that certain aspects — including references to the Duke’s past litigation with other newspaper groups, which Mr Justice Nicklin has already ruled inadmissible — should be removed. The trial is due to begin in January 2026 and is expected to last nine weeks.
Court Drama Unfolds
Wednesday’s hearing saw dramatic scenes as actress Sadie Frost and filmmaker David Furnish attended in person, whilst other claimants joined remotely via video link.
In a moment of unexpected levity, Prince Harry himself used the video system to send a message to Baroness Lawrence after her microphone picked up a conversation. “Doreen, please mute your phone,” he said, demonstrating his continued active involvement in the proceedings.
Financial Stakes Soar
The legal battle has already proven extraordinarily expensive. High Court judges on Friday branded the estimated £38 million legal costs as “manifestly excessive” and “disproportionate”, with claimants aiming to spend approximately £18.7 million and the publisher £19.8 million.
Mr Justice Nicklin and Judge David Cook “had little difficulty concluding that such sums were manifestly excessive and therefore disproportionate,” slashing the approved budgets to approximately £4 million for each side.
Victory Against The Sun
The revelations come just days after Harry secured a major victory in his separate case against News Group Newspapers (NGN), publisher of The Sun. After five years of legal battles, NGN agreed to pay “substantial damages” believed to exceed £10 million and issued a “full and unequivocal apology” for serious intrusion into his private life, including incidents involving his late mother, Princess Diana.
Harry described the settlement as a “monumental victory”, stating that “News UK is finally held to account for its illegal actions and its blatant disregard for the law.”
Royal Family Tensions
The decision to bring William and Kate into the legal proceedings marks a significant escalation in Harry’s campaign against the British press. The brothers’ relationship has been severely strained since Harry and his wife Meghan stepped down from royal duties in 2020 and relocated to California.
The timing is particularly sensitive, coming as the Princess of Wales continues her recovery from cancer treatment and the Royal Family attempts to present a united front amid various challenges facing the monarchy.
By revealing alleged surveillance of his brother and sister-in-law, Harry risks being seen as betraying family privacy whilst claiming to protect his own. The irony is not lost on royal observers that in pursuing privacy violations, the Duke has effectively made public previously unknown allegations about surveillance of the future King and Queen.
What Happens Next
Associated Newspapers has strenuously denied all allegations and told the court the claims were “simply preposterous.” Given its “entrenched positions,” the publisher does not see a settlement similar to Harry’s deal with NGN as possible.
The trial against ANL is scheduled for January 2026, but these latest revelations about William and Kate’s alleged surveillance could prompt fresh attempts at settlement negotiations or, conversely, harden positions on both sides.
Harry’s legal team argues that these documents demonstrate a pattern of systematic intrusion into the private lives of the Royal Family, whilst ANL maintains the allegations are unfounded and brought far too late under legal time limits.
Wider Implications
The case highlights the complex relationship between the Royal Family and the British press, a dynamic that has shaped public perception of the monarchy for generations. Harry’s mother, Princess Diana, famously blamed press intrusion for many of her difficulties, and her death in 1997 whilst being pursued by paparazzi in Paris remains a defining trauma for both princes.
Now, by revealing alleged surveillance of William and Kate dating back to their early relationship, Harry has opened a new chapter in this troubled history. The evidence suggests that the woman who would become the future Queen Consort was allegedly subjected to the same invasive tactics that Harry claims destroyed his mother’s life and continues to threaten his own family’s security.
As the case progresses toward its 2026 trial date, the Royal Family faces the uncomfortable prospect of further revelations about press intrusion into their private lives. Whether this will ultimately bring the brothers closer together in shared outrage, or drive them further apart through public exposure of private matters, remains to be seen.
The Palace has declined to comment on the ongoing legal proceedings, maintaining its traditional stance of not engaging with matters before the courts. But behind palace walls, the ramifications of Harry’s latest legal salvo are sure to be keenly felt.
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