Britain's Prince Harry leaves after attending the National Service of Thanksgiving at St Paul's Cathedral during the Queen's Platinum Jubilee celebrations in London, Britain, June 3, 2022. (Reuters)

As part of his own case, Prince Harry's brother Prince William allegedly "recently settled" a phone-hacking claim against a UK newspaper group, as per court records submitted by Harry on Tuesday.

Harry, 38, is prosecuting a number of UK newspapers over alleged unlawful information-gathering, most notably News Group Newspapers (NGN), which publishes The Sun and the now-defunct News of the World tabloids.

NGN, a division of Rupert Murdoch's global publishing conglomerate, is requesting that the High Court in London dismiss the lawsuits filed by Harry and Hugh Grant because they are out of time.

The Prince's attorneys, however, claimed that William has "recently settled his claim against NGN behind the scenes" in documents submitted for a three-day hearing this week.

Kensington Palace rejected to comment on behalf of Prince William, whose formal title is the Prince of Wales.

The court documents also contain assertions made by Harry that a "secret agreement" between the royal family as an institution and the publisher is to blame for the delay in bringing legal action against NGN.

They claim that Queen Elizabeth II, the late grandmother of the princes, participated in "discussions and authorization" of the agreement, which barred royals from bringing claims against NGN until other alleged hacking cases had been resolved.

"The reason for this was to avoid the situation where a member of the royal family would have to sit in the witness box and recount the specific details of the private and highly sensitive voicemails that had been intercepted," Harry said in a witness statement.

"The institution was incredibly nervous about this," he stressed, with the documents pointing out that Harry was knowledgeable of the agreement in 2012.

"This agreement, including the promises from NGN for delayed resolution, was, obviously, a major factor as to why no claim was brought by me at that time," he added.

In 2021, NGN resolved allegations of phone hacking made by more than a dozen well-known people, including actress Sienna Miller.

It is worth noting that Harry and singer Elton John are two of six notable persons who have filed a lawsuit against the Daily Mail's publisher for alleged illegal information collecting at its publications.

The Prince is also anticipated to testify in a case involving accusations of illegal information gathering against tabloid publisher Mirror Group Newspapers (MGN).

Harry appeared in court earlier this month to begin his legal battle with the Daily Mail's parent business. In the upcoming weeks, a judge will decide whether or not that case may go to trial. Next month, Harry will likely testify in court as a witness in connection with his other phone-hacking claim against the parent company of the Mirror.