LONDON — In July, the author Xiaolu Guo was expecting the delivery of a book that would not be published until September: Margaret Atwood’s “The Testaments,” the highly anticipated follow-up to “The Handmaid’s Tale.”

Guo was getting her copy so early because she is a judge for this year’s Booker Prize, Britain’s most prestigious literary award. There was just one problem, Guo said in an interview on Tuesday: When the courier turned up, she was late getting home from the airport. The courier refused to give the book to her brother and sister-in-law, who were visiting from China.

[ Read our review of “The Testaments.” ]

Guo missed the courier’s visit the next day, too, as she was out running errands. By the time she finally got the book, she was furious, she said.

“For me, it was quite over the top, the whole security issue,” Guo added, laughing.

The secrecy around Atwood’s new novel, which is on the Booker Prize shortlist that was announced this week, has complicated the judging process this year. The prize’s organizer had to sign a nondisclosure agreement on behalf of all the judges, said Peter Florence, the chairman of the judging panel .