AFTER his mother’s death, Simon Worrall found a chocolate box full of letters in the attic telling the story of her love for Martin Preston.

Nancy Whelan met Mr Preston when he was a student in Oxford in 1938 and the couple were in love and engaged to be married when the Second World War broke out. Mr Preston enlisted, travelling to Northern France in January 1940, but within a short time his letters stopped and he was never heard from again.

The Second Lieutenant is thought to have died while manning a machine gun post in Hazebrouck, northern France.

The true story has prompted Mr Worrall, 66, to write the novel The Very White of Love, published next month by HarperCollins imprint HQ.

Mr Worrall said in his afterword: “I had always known of Martin’s existence.

“Right up to my mother’s death, under the glass on her dressing table, next to pictures of my father and her three children, she kept a faded photograph of him, sitting on a bench in a cricket blazer, his face turned to the right and one hand resting on his knee. Dark shadows under his eyes give him a dreamy, faraway look.”

Mr Worrall said reading Mr Preston’s letters 70 years on was like meeting a long-lost family member.

He added: “The mysterious young man in the photograph had acquired a voice; a character - it was a writer’s gift.

“By telling the story of this brief and beautiful relationship I wanted to rescue it from oblivion and make good on the hope expressed in one of Martin’s letters from France that this love ‘can’t all be there for nothing’.”

Nancy Whelan met Philip Worrall in 1946 in Prague and they married in 1946. After marrying and starting a family, and up until her death in 2005, a photo of Martin Preston sat on her dressing table.

The author had known of the soldier’s existence but not the whole story and through reading the letters he began to piece together the tragic tale.

By recreating Mr Preston’s journey through France, Mr Worrall was able to track down the final known location of Martin’s battalion with the Oxfordshire and Buckinghamshire Light Infantry, although not conclusive details about what had happened to Mr Preston.

He was in one of the battalions that formed the perimeter guard around Dunkirk and held back the German troops while the evacuation was completed.

Mr Worrall hopes the story will resonate with many families with lost fathers and ‘could-have-been-fathers’ from the Second World War.

He added: “For me, this other man, who had once occupied such a significant place in my mother’s heart, was both a stranger and an intimate. A shadow from the past, an enigma, an alternative narrative.

“Sometimes, if my father and I had had a falling-out, I would wonder what it would have been like if Martin had been my father.”

The Very White of Love by SC Worrall is published on June 14 by HQ, price £14.99.

The author has written for National Geographic, GQ, The Times and The Guardian. He will be at Waterstone’s in Oxford to talk about his novel on Thursday, June 28. The talk costs £3.