The Prince of Wales recently settled a phone hacking claim against publisher News Group Newspapers for a “very large sum”, the High Court has been told.

Prince William received the payment in 2020 after bringing a legal claim against the owner of the Sun and the News of the World.

Details of the settlement were revealed in legal documents submitted by his brother, the Duke of Sussex, as part of his legal battle with the same publisher.

He also claims in court documents that the late Queen was personally involved in a secret agreement between Buckingham Palace and Rupert Murdoch’s newspaper group.

The agreement meant members of the Royal family would not make legal claims over phone hacking until other court battles had been completed in exchange for an apology at a later date, it is alleged.

News Group Newspapers (NGN), the publisher of The Sun and the now-defunct News of the World, denied any secret agreement with the palace. A spokesman offered no comment. Buckingham Palace declined to comment.

News of Prince William’s settlement came to light on Tuesday as a three-day hearing in London, involving Prince Harry and the actor Hugh Grant, got under way.

The Duke of Sussex is suing NGN over alleged unlawful information-gathering at its titles. NGN is asking Mr Justice Fancourt to throw out both claims, arguing that they have been brought too late.

Court documents submitted on behalf of Prince Harry’s legal team allege that his brother settled a claim against the publisher for a “very large” amount of money.

“HRH William, Prince of Wales, similarly brought a claim against NGN which it settled for a very large sum of money in 2020,” the documents state.

There are no further details about what Prince William alleged took place and whether it related to the Sun or the News of the World.

Responding to the publisher’s strike out application in court, Harry’s lawyers said it was an attempt to go behind a “secret agreement” between the Royal family as an institution and NGN, of which the Duke was informed in 2012.

In documents before the court, David Sherborne, representing Prince Harry, said the late Queen was involved in “authorisation” of an agreement that members of the Royal family would not pursue claims against NGN until after the conclusion of the litigation over hacking.

Mr Sherborne said in written arguments that the agreement “meant that the claimant could not bring a claim against NGN for phone hacking at that time”.

The result of the alleged deal was that the princes would delay legal proceedings against the newspaper group in return for receiving an apology at a later date.

A statement from Prince Harry in the court documents claims: “My brother and I were also told by either the institution’s solicitor ... or someone else from the institution that there was no possibility of either of us bringing a claim against NGN for phone hacking at that time.

“The rationale behind this was that a secret agreement had been reached between the institution and senior executives at NGN, whereby members of the Royal family would bring phone hacking claims only at the conclusion of the mobile telephone voicemail interception litigation and at that stage the claims would be admitted or settled with an apology.

“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 by Clive Goodman.”

The statement adds that “the institution” was “incredibly nervous about this”.

It continues: “[It] wanted to avoid at all costs the sort of reputational damage that it had suffered in 1993 when The Sun and another tabloid had unlawfully obtained and published details of an intimate telephone conversation that took place between my father and stepmother in 1989, while he was still married to my mother.

“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.”

The hearing is expected to last three days and the judge will determine whether the claims will progress to a trial, due to be heard in January.

The claim is one of a number of legal actions currently being brought by the Duke, who appeared in person at the High Court last month for a preliminary hearing against Associated Newspapers Limited, the publisher of The Mail and The Mail on Sunday.

He is also expected to give evidence at a trial over allegations of unlawful information against the tabloid publisher Mirror Group Newspapers, due to begin next month, with Prince Harry due to appear in court in June.

Kensington Palace declined to comment on behalf of the Prince of Wales.