For the first time, the Man Booker International prize could go to an anonymous writer this year, if a story of lifelong friendship in southern Italy beats the other five contestants in a short list announced this week. "The Story of the Lost Child", the fourth and final instalment in a tale of friendship, family and power centered on noisy Naples, is up against rivals that include Turkish Nobel Prize winner Orhan Pamuk. The true identity of its writer, who has published this series and three other books under the pen name Elena Ferrante, is one of the best-kept artistic secrets in modern Italy. "Elena Ferrante was born in Naples. This is all we know about her," the Booker Prize Foundation said on its website. A spokeswoman for the prize said no anonymous writer had ever won the Man Booker Prize or the Man Booker International Prize. Before publishing her first novel, Ferrante is widely quoted as having said in a letter to her publishers, "Books, once they are written, have no need of their authors." Even as the "Neapolitan Novels", the first of which came out in Italy in 2011, drew worldwide acclaim and sales reportedly exceeded 1 million copies, she did not identify herself.

Speculation about her identity reached its zenith in March when literature scholar Marco Santagata posited that her real identity was that of a Naples university professor who lived for a time in the Tuscan town of Pisa, like the Elena of the novels. The professor, Marcella Marmo, said she was not a writer.

Suggestions on social media that she might be a man were received with scepticism because of the sensitivity of her portrayals of female adolescence, friendship and the sometimes fraught relationships between mothers and daughters.

Ferrante's publishers know her true identity, but even her co-nominee for the 50,000-pound ($70,770) Booker International prize, New York-based translator Ann Goldstein, is in the dark.

"I've translated a lot of dead writers so I'm kind of used to not having contact with the writer," Goldstein told Reuters by telephone, with a chuckle.

"I think it's admirable that she's made this decision to have nothing to do with her books once she's written them."