A man who claims that one of JK Rowling's Harry Potter books was lifted from another work has lost his appeal against an order that he should pay £1.5 million (NZD$2.87 million) into court as security for costs in his forthcoming copyright action.

Paul Allen, trustee of the estate of Adrian Jacobs, who died in 1997, alleges that the fourth in the series - Harry Potter and the Goblet of Fire - was plagiarised from Mr Jacobs' book, Willy the Wizard.

Allen is suing Rowling and her publisher, Bloomsbury, for some 5 million, with the trial due next February.

Last year, High Court judge Mr Justice Kitchin rejected an application by Rowling and Bloomsbury to strike the case out - although he said it had only an "improbable" chance of success.

But in March this year, he ordered Allen to make a series of staged payments into court by November 11 for 65 per cent of the costs faced by Rowling and Bloomsbury.

Today, three judges in London rejected Allen's appeal on the basis that Mr Justice Kitchin's treatment of the issues before him was "an entirely proper exercise of his discretion".

Lord Justice Rix, Lord Justice Lloyd and Lord Justice Sullivan also said that if the first payment was not made by the end of tomorrow, the case would be struck out.

Rowling has described Mr Allen's claim as "not only unfounded but absurd", saying she had never even seen Willy the Wizard until the action was launched in 2004.

The latest stage in the litigation comes on the day Potter fans will gather at British cinemas for the midnight screening of the epic finale - Harry Potter and the Deathly Hallows Part 2.