Bookshops clamour for copies of JK Rowling's secret book The Cuckoo's Calling

The book only sold 1,500 copies under Rowling's pseudonym, Robert Galbraith

JK Rowling offered her latest work under a pseudonym to other publishers but was rejected (AP)

Book sellers have implored the publisher of The Cuckoo’s Calling to rush out a reprint as quickly as possible, as many ran out of copies shortly after JK Rowling was unmasked as the author.

Little, Brown, which published the detective novel, has printers Clays “working around the clock” to get copies into the bookshops by the end of the week.

The Cuckoo’s Calling was released initially in April to good reviews, but sold around 1,500 copies in hardback.

The publisher would not reveal how many copies would be reprinted, but Alison Hennessey, the senior crime editor at rival publisher Harvill Secker wrote on Twitter: “Woah. Apparently Little, Brown are now reprinting 300,000 copies of The Cuckoo’s Calling.” Little, Brown has not responded over whether the rumoured figure is accurate.

The work was attributed to Robert Galbraith, described as a former military man with two children.

Yet, on Sunday, Galbraith was revealed to be the pseudonym of Ms Rowling, author of the bestselling Harry Potter series. Just hours after the news, the book topped Amazon’s bestseller’s chart in the UK.

Jasper Sutcliffe, head of buying at Foyles, said: “It has been fantastic, a complete surprise. Unfortunately we did not have a lot of stock in.”

Foyles and Waterstones revealed that most of the copies were snapped up, and Mr Sutcliffe said there was a “huge backlog of customer orders,” adding: “It’s crucial we get them for this weekend while there’s still a big buzz.”

The publisher would not reveal how many copies it had requested for the reprint, but said it aimed to have a new batch in stores by Friday. A spokesman for Waterstones called it a “gift for the book trade. It will be one of the biggest books of the year.”

The reprint will include a new author biography reading: “Robert Galbraith is a pseudonym for JK Rowling, author of the Harry Potter series and The Casual Vacancy.” This coincides with the publication of the paperback version of The Casual Vacancy on Thursday.

Ms Rowling called being Galbraith “such a liberating experience” and added: “It has been wonderful to publish without hype or expectation, and pure pleasure to get feedback under a different name”.