The Duke of Sussex can continue his unlawful information gathering claim against the publisher of the Daily Mail, after a High Court judge concluded that it had failed to deliver a “knockout blow” to the royal’s legal challenge.

Singer Sir Elton John and campaigner Baroness Doreen Lawrence can also pursue their legal action against Associated Newspapers (ANL) following a preliminary ruling that they had “a real prospect” of showing that alleged unlawful activities were concealed from them.

The trio are among a group of high-profile individuals – including Sir Elton’s husband David Furnish, actresses Sadie Frost and Liz Hurley and ex-MP Sir Simon Hughes – accusing the publisher of carrying out or commissioning unlawful activities such as hiring private investigators to place listening devices inside cars, “blagging” private records and accessing and recording private phone conversations.

ANL, which firmly denies the allegations, had asked a judge at a hearing in March to rule in its favour without a trial, arguing the legal challenges were brought “far too late”.

But in a ruling on Friday, Mr Justice Nicklin said ANL had “not been able to deliver a ‘knockout blow’ to the claims of any of these claimants”.

Lawyers for Harry and others said they were “delighted” with the ruling.

The cases remain at an early stage and ANL has yet to file a formal defence, with a further hearing due on November 21.

ANL said in a statement: “As we have always made unequivocally clear, the lurid claims made by Prince Harry and others of phone-hacking, landline-tapping, burglary and sticky-window microphones are simply preposterous and we look forward to establishing this in court in due course.”

The judgment raises the prospect of a third High Court trial centred around Harry’s allegations of unlawful information gathering against major newspaper publishers.

The duke gave two days of evidence from the witness box during the trial of his damages claims against Mirror Group Newspapers (MGN), now known as Reach, which publishes The Mirror, earlier this year.

A ruling is still expected in the MGN case, while Harry’s legal action against News Group Newspapers (NGN), publisher of The Sun and the now-defunct News of the World, is set to head to trial in January 2025.

In his 95-page-judgment, Mr Justice Nicklin said that each of the seven people in the ANL claim have a “real prospect” of demonstrating that ANL concealed “relevant facts” that would have allowed them to bring a claim against the publisher earlier.

“Whilst it is common ground that the publication of any unlawful articles was not concealed, these were, on the claimants’ case, only the tip of the iceberg,” the judge continued.

“What was deliberately hidden from the claimants – if they are correct in their allegations – were the underlying unlawful acts that are alleged to have been used to obtain information for subsequent publication.”

Mr Justice Nicklin also said the group bringing the legal challenges had “a real prospect of demonstrating not only that the unlawful acts themselves were concealed, but also, in many instances, further devices were employed in the published articles to throw the subject ‘off the scent’”.

He continued: “Several claimants complain that they believed that their confidences were being betrayed by people close to them.

“Depending upon what the evidence shows, this may be a significant factor on the issue of both concealment and the point at which any claimant could have been expected to begin investigating whether, in fact, the true source of private information appearing in articles was unlawful information gathering, rather than treacherous friends.”

ANL argued that, “given his position and profile”, his “suspicions” over the behaviour of journalists and awareness of phone-hacking by another newspaper publisher, the Duke of Sussex could have brought his case earlier, the judge said.

But Mr Justice Nicklin said ANL’s case “rather ignores” the “firm denials” of wrongdoing given by Paul Dacre, the former editor of the Daily Mail, at the Leveson Inquiry into press standards to which Harry “says he did attach importance”.

The judge also concluded that the “fair resolution” of any issue over the timing of the claims being brought “must await trial”.

ANL also argued that parts of the cases brought against it rely on documents that were provided by the company to the Leveson Inquiry in 2011 and 2012 with the understanding that they were confidential.

The publisher said these documents are subject to publication restriction orders over their use, and that lawyers for Harry and others are in breach of these by relying on them without first applying for their disclosure.

Harry’s legal team said the material was not covered by the inquiry’s restriction orders, but Mr Justice Nicklin ruled on Friday that the restrictions remain in force and that documents could not be used.

ANL said this decision was a “significant victory for justice and the Mail”.

Harry made a surprise appearance at the Royal Courts of Justice during the four-day preliminary hearing earlier this year, with Sir Elton and Lady Lawrence also appearing at the London court at times during proceedings.

Next steps in the case will be considered at the hearing later this month, where any bids by ANL to appeal against the ruling could be considered.