Amsterdam, The Netherlands - The Dutch national archive says it has gathered information about the arrests and deportations of some 9,000 Dutch Jews who died in Nazi concentration camps in World War II.
The project was carried out by journalist Ad van Liempt and team of investigators at the archive who were allowed access to the dossiers of 250 collaborators who have since died.
The dossiers centered around the "Henneicke Column," which tracked down Jews with police help, often paying money for tips.
Records of convicted World War II collaborators are sealed under Dutch privacy laws. Results of the project are only available to victims' families.
An estimated 110,000 Dutch Jews died in the Holocaust, including teenage diarist Anne Frank. Around 30,000 survived.