A book about how a Jewish girl was protected during the Holocaust - which failed to make the longlist for Britain’s pre-eminent Jewish literary prize - has won the Costa Book of the Year award.

The Cut Out Girl by Bart van Es, professor of English at Oxford University, tells the story of Lien de Jong, who as a young Jewish girl was sheltered by the author’s grandparents in Nazi-occupied the Netherlands during the Second World War. Lien later became estranged from the van Es family, and the author set out to find out why.

The book was announced as the winner of the £30,000 Costa award on Tuesday evening, with the judges describing it as "sensational and gripping - the hidden gem of the year".

Ms de Jong, now 85, attended the Costa ceremony, where she described how she did not speak about what happened to her until Prof van Es approached her.

She added: "Nobody spoke about it during the war or after the war... The time before that, I had no words. I never thought I had a story but Bart wrote it down and it was a story."

Professor van Es told the JC that the book had been "healing and helpful" for his family and for Lien and her family, some of whom live in Israel.

"I feel I have gained them as cousins," he said. "It's a great thing that everyone has found the book an enrichment. Now, thanks to the Costa Prize, it will be shared with more readers, which is wonderful." 

The win comes after the JC’s chief fiction reviewer David Herman noted that the JQ Wingate Prize shortlist contained “no history books or biographies in a good year for both”, specifically citing The Cut Out Girl's absence. 

The book had also failed to make the prize's longlist of 13 books, announced in December. 

Now in its 42nd year, the JQ Wingate Prize, worth £4,000 and run in association with the JW3 Jewish community centre, is awarded to "the best book, fiction or non-fiction, to translate the idea of Jewishness to the general reader.”

Shoshana Boyd Gelfand, the Wingate Prize's chair of judges, told the JC: “We are looking forward to announcing the winner of the JQ Wingate prize on February 25 at a panel event [at JW3] where the judges will shed light on the process and their choices.

“The recent announcement of The Cut-Out Girl as the winner of the Costa prize just demonstrates how many superb books there were to choose from this year and how differently each judging panel fulfils their mandate.”