A book about a Dane's efforts to save thousands of Chinese refugees during the Nanjing Massacre was launched here Monday, unveiling a little-known part of World War II history.

Written by senior Chinese journalist Dai Yuanzhi, the book, 1937-1938: A Dane in Bloodstained Nanjing - Testimony on Humanity and Violence, documents historical events and the story of Bernhard Arp Sindberg, the Dane who sheltered thousands during the massacre.

Sindberg, who served as an employee of the Danish company F.L. Smidt at the Jiangnan Cement Plant outside Nanjing, protected refugees at the plant together with a German citizen, Karl Gunther, between late 1937 and early 1938.

Invading Japanese troops occupied Nanjing in eastern China on Dec. 13, 1937, and began a six-week massacre. Chinese records show more than 300,000 people - not only disarmed soldiers, but also civilians - were murdered.

Over nearly ten years of research, Dai pieced together Sindberg's notes and photos.

According to the book, Sindberg documented a number of war crimes committed by the Japanese troops and delivered the report to the International Safety Committee in Nanjing. He also took part in revealing the Nanjing Massacre to the media and others in Geneva after he left China in 1938.

Chinese people are comparatively more familiar with John Rabe, a German who rescued a large number of Chinese people during the Massacre.

During the book launch ceremony, the Danish Ambassador to China, Jeppe Tranholm-Mikkelsen, said he hoped the book will help ordinary people understand the historical relationship between Denmark and China.

"This first book on Sindberg helps us to get a much more complete picture of his life, personality and not least his humanitarian efforts,"the ambassador said.

Denmark and China witnessed the 60th anniversary of their establishment of diplomatic ties this year.