The Duke of Sussex has made a surprise appearance at a High Court hearing in London as the Daily Mail’s publisher makes a bid to throw out a set of claims over alleged unlawful information gathering at its titles.

Associated Newspapers Limited (ANL) is bringing a bid to end High Court claims brought by people including Harry, Sir Elton John and Baroness Doreen Lawrence over the allegations – which include the hiring of private investigators to secretly place listening devices inside cars and homes and the recording of private phone conversations.

The group of high-profile individuals, also including Sir Elton’s husband David Furnish and actresses Liz Hurley and Sadie Frost, announced in October they were bringing claims for misuse of private information against ANL.

Their lawyers said at that time the group have “become aware of compelling and highly distressing evidence that they have been the victims of abhorrent criminal activity and gross breaches of privacy” by ANL, which is also the publisher of The Mail On Sunday and MailOnline.

Harry arrived at the Royal Courts of Justice in London for the start of the four-day hearing on Monday, sitting towards the back of the courtroom and occasionally taking notes in a small black notebook.

Monday’s appearance is believed to be the first time Harry has been back in the UK since the late Queen’s funeral in September.

His surprise return comes nearly three months after he laid bare his troubled relationship with his father the King and brother the Prince of Wales in his controversial autobiography Spare.

Ahead of the start of the afternoon session of the hearing, Sir Elton was also seen arriving at the central London court.

ANL’s lawyers have said the claims brought by seven high-profile individuals including the Duke of Sussex and Baroness Lawrence should be dismissed without a trial.

Adrian Beltrami KC, for ANL, said in written submissions that the legal actions have been brought too late and are “stale”.

The barrister said the individuals have to prove they did not know earlier, or could not have discovered earlier, they may have been able to bring a claim against ANL for alleged misuse of their private information.

Mr Beltrami said that more than a decade after the Leveson Inquiry and several criminal and civil proceedings over phone hacking, “it would be surprising indeed for any reasonably informed member of the public, let alone a figure in the public eye, to have been unaware of these matters”.

He continued: “The claimants have failed to show that they have a real prospect of discharging their burden at trial and the court should not hesitate to dismiss these stale claims at an early stage, thereby avoiding what would otherwise be a considerable waste of time, costs and the court’s resources.”

David Sherborne, for the group, said the unlawful acts in the claim include commissioning the “breaking and entry into private property”, illegally intercepting voicemail messages, listening to live landline calls and obtaining medical records.

He said in written submissions: “The claimants each claim that in different ways they were the victim of numerous unlawful acts carried out by the defendant, or by those acting on the instructions of its newspapers, The Daily Mail and The Mail On Sunday.

“They range through a period from 1993 to 2011, even continuing beyond until 2018,” the barrister added.

A spokesperson for ANL previously said the allegations were “unsubstantiated and highly defamatory claims, based on no credible evidence”.

Mr Beltrami said that Harry “does not offer any reason why he could not with reasonable diligence have discovered the basis for his inferential claim against Associated before October 2016”.

Quoting from documents filed on Harry’s behalf, Mr Beltrami said in written arguments that the duke’s case was that “suspicion and paranoia was caused by Associated’s publication of the unlawful articles: friends were lost or cut off as a result and everyone became a ‘suspect’, since he was misled by the way that the articles were written into believing that those close to him were the source of this information being provided to Associated’s newspapers”.

He added: “He stated that ‘the repeated, wrongful disclosures … had a serious and profound effect upon (him) at the time of their publication’ and that he had ‘painful memories … regarding the extent to which ANL publicised private and sensitive information relating to his private and family life’.”

The hearing before Mr Justice Nicklin is due to conclude on Thursday.