LONDON -- The mystery has been solved.
A British law firm admitted Thursday one of its partners inadvertently revealed J.K. Rowling had authored a mystery novel, The Cuckoo's Calling.
The Sunday Times revealed during the weekend the Harry Potter author had penned the book under the pseudonym Robert Galbraith.
The newspaper said it had received a tip on Twitter, and there was speculation Rowling or her publisher were behind the revelation -- which has sent sales of the thriller skyrocketing.
But law firm Russells said Thursday that one of its partners, Chris Gossage, had let the information slip to his wife's best friend, Judith Callegari -- the woman behind the tweet. Her Twitter account has now been deleted.
Russells said in a statement that "we apologize unreservedly" to Rowling.
It said that while Gossage was culpable, "the disclosure was made in confidence to someone he trusted implicitly."
"We can confirm that this leak was not part of any marketing plan and that neither J.K. Rowling, her agent nor publishers were in any way involved," the statement said.
The Cuckoo's Calling had garnered good reviews but sold in the hundreds of copies since being published in April, ostensibly as the first novel of a former soldier. Since Rowling was outed as the author, it has topped bestseller lists, with publisher Little, Brown and Company commissioning a new printing of 300,000.
-- The Associated Press