Jewish-American writer Courtney Zoffness has won the 2018 Sunday Times EFG Short Story Award for her story Peanuts aren’t nuts.

She is the second woman to win the prize, worth £30,000 and considered the most prestigious award for an English-language single short story, with entries from around the world.

Previous winners and shortlisted authors have included Hilary Mantel, Ali Smith and Junot Diaz.

Ms Zoffness’s short story explores the challenging relationship between a Jewish high school student, Pam, and her biology tutor, Mr Peebles, who is arrested in a child-predator sting.

The story is based on the author's own personal experience of being taught by someone who was subsequently imprisoned on child pornography charges.

In an interview with the Sunday Times, Ms Zoffness, who does not have a literary agent, joked: “I’m the mysterious dark horse, aren’t I?”

She called the prize “life-changing”, saying: “I have been at this game, albeit quite quietly, for a while, and I do feel like it took some time for me to find my voice as a writer, and I feel like I’ve found it now.

"Short stories don't have latitude for wasted words or tangents. As a literary writer who values diction and cadence as much as drama, I love working in a form that not only embraces such close attention to language, but depends on it."

Ms Zoffness, 39, lives in Brooklyn, New York, and is currently an assistant professor of English and director of the creative writing programme at Drew University, New Jersey. She is currently turning her short story into a full-length novel.

"There was something about Peanuts Aren’t Nuts that spoke to all of us,” Sebastian Faulks – who judged the award - said in a statement.

“The narrative arc was beset by dangers and required immaculate judgment of tone. It was a high-tariff endeavour, exactly brought off.

“And at its heart it had that precious thing that underlies the best fiction. It’s not just about giving a voice to the overlooked; it is about valuing the inner world above the outer – dramatically reminding us that this quiet place is where lives are shaped."

The result was announced on Thursday at a gala dinner at Stationers’ Hall in London.