Leading human rights lawyer Philippe Sands has won the £30,000 Baillie Gifford literature prize for his compelling family memoir East West Street: On the Origins of Genocide and Crimes Against Humanity.

Professor Sands received the prestigious award at a ceremony in London on Tuesday evening.

His book details the horrors of Nazism, beginning and ending with the Nuremberg trials of 1946, and tracing the lives of of two influential jurists, Hersch Lauterpacht and Rafael Lemkin as well as Hans Frank, the former Governor-General of Poland who was found guilty at Nuremberg.

Against this backdrop, he integrates his personal family history into the larger story.

Prof Sands, who is a professor of law at University College London and a barrister at Matrix Chambers, said: “As a litigator you are a storyteller. East West Street is really a double detective story. It’s a search to unlock a family secret: the circumstances in which my grandfather and my grandmother, along with my mother, left Vienna in the course of the years that followed.

“And then it’s a detective story about the origins of crimes against humanity and genocide: two subjects that occupy my life as an academic but also as a practising lawyer doing cases in international courts.”

Stephanie Flanders, chair of the judges, said Prof Sands had “pulled off something extraordinary with this book that deserved to reach as wide an audience as possible.”

She added: “This is not just one story but several different stories, woven together - each important and each deeply personal to the author. The result is a multi-layered history that is impressive in its own right but also a satisfying, suspenseful read. A stunning achievement."

The three other titles shortlisted were Svetlana Alexievich’s Second-Hand Time, Margo Jefferson’s Negroland: A Memoir and Hisham Matar’s The Return: Fathers, Sons and the Land in Between.

Prof Sands announced that he would split the £30,000 prize with Mr Matar, not only a fellow shortlistee, but also a close friend. He promised that the money would be donated to a refugee charity - “minus the cost of a bottle of cognac for Hisham and a jar of pickles for me.”