Bestselling Scottish crime novelist Ian Rankin has quashed a report that speculated about Harry Potter author J.K. Rowling's next foray into fiction.

The Sunday Times had quoted Rankin as saying his wife had glimpsed Rowling — who lives in the same Edinburgh neighbourhood — hard at work on a detective novel in a local café.

"This is a joke that got out of hand," Rankin said in an interview with the Guardian newspaper.

According to Rankin, he had made the remark — which he said was a joke — on stage during an event at the Edinburgh book festival.

Emma Schlesinger, a spokeswoman for Rowling's literary agent, Christopher Little, also said the speculation about a Rowling crime novel was "unfounded."

"J.K. Rowling is taking a well-earned break following the English language publication of Harry Potter & the Deathly Hallows and there are no firm plans as yet as to what her next book may be," Schlesinger said.

Last month, Rowling told U.S. media that she was working on two new books: "One is for children and the other is not for children."

The author's blockbuster series came to a record-breaking finale with the English-language release of Harry Potter and the Deathly Hallows on July 21.

More than 11 million copies were sold in the first 24 hours of release. The first six books in the Harry Potter series have sold more than 325 million copies worldwide and been translated into more than 60 languages.