As Prince Harry steps into the witness box at London's High Court for the phone hacking case against Mirror Group Newspapers (MGN), his father, King Charles, and brother, Prince William, are reportedly concerned. This information comes from Katie Nicholl, a royal author and Vanity Fair correspondent, who recently spoke to Entertainment Tonight. It's important to note that International Business Times was unable to independently verify these claims.

Speaking to ET, Nicholl shared, "From what I gather, both King Charles III and Prince William expressed reservations about Harry's court appearance," without revealing her sources. "Considering what surfaced from Harry's evidence and witness statement, their concerns seem understandable."

Prince Harry has initiated legal proceedings against three UK publishing firms: MGN, the Daily Mirror's publisher; News Group Newspapers (NGN), the publisher of The Sun; and Associated Newspapers Limited (ANL), which owns the Daily Mail and Mail on Sunday. Harry alleges these publishers, their journalists, and their associates committed unlawful acts, including phone tapping, to invade his privacy. However, the accused publishers refute the allegations, arguing that some claims were made too late.

Documents disclosed in court in April, part of Harry's case against NGN, claimed that Buckingham Palace had previously reached an agreement with the newspaper group, delaying Harry's legal claim, according to BBC. Harry revealed this alleged agreement only came to his knowledge in 2012.

The same documents also suggested King Charles tried to dissuade Harry from pursuing legal action against the alleged phone hacking. Harry maintains that he was asked to abandon the lawsuit in 2019 because of its potential impact on the entire royal family. He attributed this to a direct request, or rather a demand, from his father, Edward Young, and his father's private secretary, Clive Alderton.

Harry also claimed that Prince William agreed to a substantial settlement for his historical phone hacking claims with the Sun publisher in 2020. However, the document did not provide the exact amount or specifics of this alleged payment.

As the main witness in the allegations of illegal information gathering against MGN, Harry faced cross-examination by Andrew Green, MGN's lawyer, earlier this week.

During his testimony, Green challenged Harry's theory that information about a thumb injury he sustained as a student, reported in the Daily Mirror in 2000, was obtained by hacking his doctor's phone. Responding to Green's accusations of "total speculation," Harry retorted, "I'm not the one who wrote the article."

Harry's case against MGN revolves around 33 articles published between 1996 and 2009. MGN denies that 28 of these involved illegal information gathering or fact-checking, while it does not acknowledge the remaining five.

Historically, in 2006, a private investigator and a reporter from the now-defunct News of the World were convicted and imprisoned for hacking phones for exclusives. The reporter apologized for tapping phones used by aides to Prince Harry, Prince William, and King Charles.