A publisher that bought the German rights to a novel for a song before learning that the author was JK Rowling is eyeing a windfall.
Blanvalet Verlag of Munich acquired the rights in February to The Cuckoo's Calling, purportedly a debut novel by Robert Galbraith, about a private detective who investigates a model's suicide.
Rowling, the British author behind Harry Potter fantasy books, has now been unmasked as the novel's actual writer.
"I never suspected it could come from Rowling," editor Anja Franzen told Focus on Sunday, adding that she had been fascinated by the novel's characters when she first read it.
Blanvalet paid a four-figure sum and was now counting on a bestseller, noting that the rights to Rowling books typically cost millions of euros.
The company, a Random House imprint, is now due for an initial print run of 200,000 copies and release in German-speaking Europe "as soon as possible".
The Sunday Times newspaper in Britain exposed Rowling as the book's author this month after suspicions were raised at how a first-time author with a background in the military could write such an assured first novel.
The book is published in English by the Little, Brown Book Group which also released Rowling's first adult novel last year, The Casual Vacancy.