As a secret-service spy, he was accustomed to covert investigations. But John de St Jorre’s greatest assignment was to discover what happened to the mother who vanished when he was a small child. Here, he picks up the trail

In 1940, when I was four years old, my mother disappeared and, with her, all trace of her existence. Growing up in London during the Second World War with my younger brother, Maurice, we were looked after by elderly spinsters and, later, sent to a Catholic boarding school. My father travelled for his work and was largely absent.

He never talked about my mother, nor did anyone else we knew. Maurice and I never discussed her either. I did not know her name and had no idea what she looked like. In those early years, it did not seem so strange being motherless because we did not know anything else.

It was only when other children – most kids had two parents in those days – asked what happened to her, we said, ‘Oh, she’s dead.’ A lot of people were dying in the bombing, so it seemed reasonable that our mother could be one of them. After the war, when I was 12 years old, my father remarried and the arrival of a stepmother further sealed off the past.