The Duke of Sussex has been ordered by a High Court judge to explain why messages which might be relevant to his lawsuit against the publisher of the Sun have been deleted.

News Group Newspapers – which also published the now defunct News of the World – had brought a one-day hearing to help gain access to documents, emails and messages related to Prince Harry’s legal claim.

The prince and more than 40 others are suing the company over allegations of unlawful information-gathering from journalists and private investigators it hired, with a trial expected to start in January 2025. NGN is contesting the claims.

Justice Timothy Fancourt said there was evidence that “a large number of potentially relevant documents” and “confidential messages” between the prince and the ghostwriter of his autobiography Spare “were destroyed some time between 2021 and 2023, well after this claim was under way”.

“The position is not transparently clear about what happened,” the judge said.

He said the prince’s exchanges with writer JR Moehringer on the Signal messaging app may have “related to the parts of Spare in which unlawful information gathering in relation to newspapers was discussed”.

NGN’s legal team accused the duke of “obfuscation” but Prince Harry’s barrister, David Sherborne, said in written arguments that the duke had not discussed unlawful information gathering via text or WhatsApp with anyone and that his Signal messages had been “wiped”.

Judge Fancourt ruled that a wider search was required of Prince Harry’s laptop, text and WhatsApp messages to look at exchanges from 2005 until early 2023.

The duke was also ordered to produce a witness statement explaining how messages with his ghostwriter JR Moehringer were missing.

News Group was awarded two-thirds of its costs, but the Duke of Sussex’s legal team is disputing the £132,000 bill, arguing the amount is excessive for a one-day hearing.

It comes after NGN’s legal team had sought an order forcing Harry to disclose any information he had which would be relevant to what he knew about alleged unlawful behaviour before the end of 2013.

NGN had argued that if the duke knew he had a potential claim before that date, then the case could be dismissed on the grounds it was filed too late.

In April, the same court rejected NGN’s request for a preliminary trial to help decide whether Prince Harry had left it too late.

Under legal rules, claims usually have to be brought within six years, but many of these cases go back decades.

But the claimants in the case argued NGN concealed evidence of phone hacking, making it impossible for them to sue sooner.

NGN has already paid out hundreds of millions of pounds to the victims of phone hacking by News of the World and settled more than 1,300 lawsuits.

The company has previously said the Sun does not accept liability or make any admissions to the allegations.

Prince Harry’s claim is one of a series of legal challenges he has brought against parts of the British press.

Earlier this year, the duke settled his remaining phone hacking claims against Mirror Group Newspapers, which related to claims of unlawful intrusion on 115 stories.