Justice Elena Kagan dismissed a plea by the Scottish author’s heirs, who aimed to delay another writer’s ability to use Holmes and his loyal assistant Dr Watson in a new book.

Kagan provided no comment as to why the request by the inheritors of Doyle’s literary rights was turned down.

But their lawyer told AFP that the heirs would follow up “in the coming months” and looked forward to presenting their arguments in a petition to review the lower court’s decision.

Holmes and Watson, Doyle characters who appeared for the first time in print in 1887, are in four of his novels and 56 stories published in the United States through 1927.

All these are in the public domain, except for the last 10 — published from 1923 to 1927 — meaning the vast majority can be used in any way without paying the Doyle estate a licensing fee.

The last 10 volumes have copyright protection until December 31, 2022.

The writer in question, Leslie Klinger, had previously published “A Study in Sherlock,” paying for the rights though he insists he did not need to do so.

But for another volume Klinger wants to call “In the Company of Sherlock Holmes,” he is resisting paying, and an appeals court on June 16 sided with him, sparking the latest court action.

The author is seeking a green light before publication.

Doyle’s heirs, however, say that the new book borrows elements from the Scottish writer’s last 10 novels and that the manuscript has not been submitted to the court.