YouTube star Zoe Sugg didn't write all of her novel Girl Online on her own, according to her publisher.
But Sugg's publisher has now confirmed that her team employed a ghostwriter to anonymously write parts of the book.
"To be factually accurate, you would need to say Zoe Sugg did not write the book Girl Online on her own," Penguin told the Sunday Times.
The use of ghostwriters is relatively common in the world of young adult fiction and celebrity books, although Sugg and her team had not previously mentioned that she had assistance on the project.
But there are clues: in the acknowledgements of Girl Online Sugg thanks "everyone at Penguin for helping me put together my first novel, especially Amy Alward and Siobhan Curham, who were with me every step of the way".
Alward is Sugg's editor while Siobhan Curham is a prolific author of young adult fiction. It is not clear to what extent or in what role Curham was involved in the writing of the book.