LONDON — A High Court judge ordered the Duke of Sussex and six other claimants to pay £9.54 million toward the legal costs of Associated Newspapers Ltd, the publisher of the Daily Mail, after they lost their case alleging unlawful information gathering.

Mr Justice Nicklin ruled that the interim payment must be completed by 4 p.m. on Aug. 28. The order followed his dismissal of all claims last month, concluding an 11-week trial in London earlier this year.

The claimants included Doreen Lawrence, Sir Elton John and his husband David Furnish, actors Sadie Frost and Liz Hurley, and former Liberal Democrat minister Simon Hughes.

During the trial, the court heard that ANL's total legal costs amounted to £34.5 million. Lawyers representing the claimants had argued for a lower interim payment of just over £7.9 million.

Nicklin ruled that ANL's costs should be determined on an indemnity basis, an unusual standard meaning the losing parties must contribute to ANL's costs without the publisher needing to demonstrate that these costs were reasonable and proportionate. The judge noted that an indemnity basis is typically applied in situations where conduct or circumstances are "outside of the norm."

In his 44-page ruling, Nicklin stated the litigation was neither "simply a case in which serious allegations were made and failed" nor "merely a hard-fought piece of litigation." He found that the claims and their pursuit involved a "combination of circumstances and conduct which took the litigation outside the ordinary and reasonable conduct of civil proceedings."

The judge criticized "the speculative and substantially inferential character of the claims at their origin" and the "exceptional breadth" of the cases. He also cited "the public presentation of allegations of serious criminality and impropriety which were not ultimately established."

Nicklin faulted the claimants for "the making and maintenance of very serious allegations against many individuals" alongside a "failure to reassess those allegations when the evidence required reassessment." The continued pursuit of "allegations which were unsupported or had ceased to be realistically maintainable" was "unreasonable to a high degree," he added.

ANL issued a statement calling the ruling "a devastating critique of an attempt to destroy a newspaper and the reputations of its journalists, editors and executives."