The Duke of Sussex is to take The Sun’s publisher to court over claims it used illegal methods to gather information on him.

Prince Harry’s case could go to trial in the High Court next year after a judge ruled on Thursday that parts of his claim can proceed.

While his allegations of some illegal methods will go to trial, a judge dismissed his phone-hacking claims.

News Group Newspapers (NGN) has denied Harry’s allegations.

Prince Harry has alleged that journalists and private investigators working for The Sun and now-defunct News of the World used unlawful methods to obtain information about him.

The latest round of the royal’s battle with the UK tabloid press revolved around at what point Harry knew enough about the alleged methods used against him in order to sue.

Under UK law, claimants usually have six years after a privacy breach in which to take action, which is relevant because some of the evidence Harry was relying on went back to the mid-1990s.

Lawyers for NGN have argued that he waited too long to bring the claim, and said it should therefore be dismissed.

But the court previously heard Harry claim that a “secret agreement” was struck between Buckingham Palace and the newspaper company which had prevented him taking legal action sooner.

In March 2023, Harry said in a witness statement that a deal between royal aides and senior executives at NGN stipulated he should delay any legal action against the company, at which time privacy breaches would be admitted or settled with an apology.

He relied on the supposed agreement to explain why he had not brought his claim years earlier, and to refute NGN’s defence that he had waited too long to seek damages.

Lawyer’s for NGN have previously disputed the existence of any secret agreement, describing it as “Alice in Wonderland stuff”.

Now a judge has ruled that some of Harry’s claim can proceed to trial, but has dismissed the parts which relate to phone-hacking.

Mr Justice Fancourt said Harry’s amended case submitted earlier this year – which was reliant on the existence of the agreement to explain why he had not taken legal action over alleged phone-hacking sooner – “did not reach the necessary threshold of plausibility and cogency”.

He said Harry knew about phone-hacking at the News of the World by 2012, and so should have sued within six years of that year.

A spokesperson for NGN called the ruling a “significant victory” for the company.

They said: “In arguing his case, the Duke of Sussex had alleged a ‘secret agreement’ existed between him/Buckingham Palace and NGN which stopped NGN from asserting that the Duke’s claim had been brought too late.

“The judge, Mr Justice Fancourt, found his claims in relation to the alleged ‘secret agreement’ were not plausible or credible.

“It is quite clear there was never any such agreement and it is only the Duke who has ever asserted there was.”

But the judge ruled that there should be a trial around other alleged methods used to get information about Harry, identified in the ruling as “blagging of confidential information from third parties, and instructing private investigators to do these or other unlawful acts”.

The judge said Harry had a “realistically arguable” case that he did not and could not know enough about any use of the methods back in September 2013, the point at which NGN argue that his six-year window to bring a claim began.

Harry says he did not have enough information to bring a claim until 2018.

The ruling said it does not take a position on whether Harry waited too long to bring a valid claim, only that “it is not sufficiently clear at this stage that it was issued too late” and should be decided at trial.

The trial will take place in 2024 or 2025.

Harry’s legal action against the Sun is one of three major claims he is making against the publishers of British tabloids.

He gave unprecedented testimony in court last month as part of his claim against the Mirror Group, and is also attempting to sue the Daily Mail and Mail on Sunday over alleged breaches of privacy.