Father Patrick Desbois, who is in Hong Kong this week, is racing against the clock to uncover the hidden atrocities of the Holocaust before it is too late.
Although the slaughter of six million Jews and people of other minority groups by the Nazis in the second world war are widely known, there is little known about the Nazi unit that shot hundreds of thousands of Jews and Roma gypsies in the former Soviet bloc from 1941 to 1944.
The French Catholic priest, 55, has uncovered mass graves in Poland, Russia, Ukraine and Belarus, where at least 1.6 million Jews were shot by the Nazis.
He is in Hong Kong this week to speak in Asia for the first time about his painstaking work. Last night, he spoke at the Jewish Community Centre at a ceremony to commemorate UN International Holocaust Remembrance Day, which is today.
He said he aims to raise awareness about the genocide and mass murder hoping to prevent these atrocities from happening again.
'For me, genocide is a disease of humanity,' he said. 'If you do not recognise a disease you cannot treat it.'