Professor Suzannah Linton, a former academic at the University of Hong Kong, will offer insight into this forgotten period in her book , to be published in August.

As well as shedding light on the trial themselves and reminding the world of the brutality of the Japanese campaign in Asia, Linton explores key issues in international law that the tribunals raised. They were part of a radical and historic shift towards individual criminal responsibility that had been made Allied policy during the war years, and which was put into practice in Europe and Asia when the war was over.

Thousands of Japanese were tried in Asia, whether by the British, Australians, Chinese or Dutch. Of these, 123 were tried by the British in Hong Kong. Linton believes these cases were part of a much neglected Asian tapestry that has become part of the bigger global picture.

"They were certainly not problem-free trials, let alone by today's standards," she said. "But, even today, with all the expertise, technology and skills involved, there are many examples of trials that go badly wrong at our international courts and tribunals. In my view, these Hong Kong trials were, warts and all, a genuine effort to do justice in a fair way, and they were remarkable for that time and place and in those conditions."

Contributors to the book have worked on many aspects of the extraordinary crimes of the second world war in Europe and Asia, as well as other war crimes - the Rwandan genocide, the horrors of Yugoslavia, the killing fields of Cambodia, the crimes against humanity in East Timor and the depravity of Sierra Leone's war. The contributors have been engaged with the legal institutions that dealt with these tragedies, Linton said, and used that expertise to draw out secrets of the Hong Kong trials.

"Those of us involved in this book have all seen the dark side of humanity in our work over the years, and we hope that this book can be seen as part of the wider project of contributing to the truth and doing justice," she said.

Despite her experience and past research, Linton was shocked at the scale of what happened in Hong Kong under Japanese occupation. In particular, she pointed to the forced displacement programme that removed a million people from the city, and the famine and starvation that preceded it.

She found it disturbing that sexual violence against civilians in Hong Kong, which is said to have been on a very large scale, was almost invisible in the tribunal reports, although they were pursued in a minor way in the cases arising from the invasion. The scale of the prisoner-of-war- camp system in Taiwan and some of the accounts of cruelty and suffering there also had a major impact on her.

She found that the atrocities in Hong Kong fitted into a clear and well-established pattern of conduct across Asia during the second world war, in Korea, China, the Philippines and the rest of Southeast Asia and the Pacific.

The abuse in Hong Kong's police stations, for example, was textbook Japanese military police practice - it was not "hi tech" and is still used by some regimes to this day: "water torture", which equates to today's waterboarding, burning, beating, and forms of forced body contortions such as "aeroplane torture".

But, she said, the way Hong Kong bounced back from this traumatic period is an example of the resilience and spirit that still pervades the city today - people pick themselves up and get on with things.

However, Linton does qualify this view when discussing the "amnesia about the past" in the introduction to her book, exploring the reasons why these trials became forgotten. Not that this experience was unique to Hong Kong. While the trials in Europe went on for years - and from time to time old Nazis are still brought to justice - the trials in Asia seem to have stopped by the end of the early 1950s.

People did not mull over the Asian trials as they did in Europe, she said. Global geopolitics meant that Japan, and West Germany, became important allies in the cold war. Even the mainland, where records of the trials of Japanese war criminals remain locked up today, half a century on, had a form of reconciliation with Japan and released incarcerated war criminals in the 1950s and '60s.

Linton believes that most people moved on and the world moved on, especially in Asia, where independence struggles erupted and new nations were born. Also, every one of the trials of the war was conducted by a victor on the vanquished.

"The Hong Kong trials were conducted by a victorious colonial power on a failed colonial power, and this pattern was repeated in Malaya, Singapore, Burma [Myanmar], Borneo and elsewhere in Asia [apart from China]," she said. "Thus, there could have been the reek of Empire's revenge associated with these trials that made forgetting about them desirable."

Linton lived and worked in Hong Kong from 2005 to 2011 as an associate professor of law at HKU, and is now chair professor of international law at Bangor University in Wales.

In June 2008 she was awarded a research grant by the Hong Kong Research Grants Council to study the war crimes trials that had been held in Hong Kong from 1946-48, but about which next to nothing was known.

"With this grant, I was able to identify the relevant files in the UK National Archives, have them electronically copied and made accessible to the public through the database that I created with the assistance of Hong Kong University libraries. This book is the culmination of that research project," she said.

Linton learned a huge amount about what happened during the war, and had insights into a forgotten legal process. Colleagues who contributed are all either legal or historical experts, and have written perceptive chapters. In their forewords, mainland judge Liu Daqun and Kevin Zervos, Hong Kong's director of public prosecutions, share their insights into the importance of chronicling this chapter of the city's past.

"We have been like archaeologists discovering a lost city in today's concrete jungle of Hong Kong," she said. "We have learned an extraordinary amount about history, and about legal issues, ranging from the procedures that governed the proceedings, to the law of war crimes used, to the concepts of individual criminal responsibility to the pleas of subordinates that they were 'only following orders'."

She hopes the book will help Hong Kong's law students realise that something very important happened here in the 1940s, and that the law can be about redeeming humanity and momentous events in history.

But above all else, Linton wants to express how very moved she was by the many people, either from Hong Kong or with links to Hong Kong, who contacted her to support the work that she had done.

"I know they will agree when I say that remembering the past in order to derive lessons for our generation is critically important, but remembering alone, as a way of honouring the victims must also be done," she said.