A further search, supported by the Dutch Military Recovery and Identification Service, learned that there were reports made of the digging up of mass graves and the reburials of the victims in anonymous graves (often on local cemeteries). Very often these reports also included an list of the identification information (Häftlingenummer). Often the digging up happened shortly after the retreat of the German troops. An inventory of the British Military Zone in 1950 showed that in Niedersachsen a majority of victims in the known mass graves had been reburied before June 1945, many even already in April 1945. The British Millitary Authorities were organizing and overseeing these reburials. After the war it was decided that all reports with information of civilians killed by German troops were to be send to the International Tracing Centre (ITC) Arolson in Bad Arolson. The reports of the French and the British were handed over to the ITS. But also the local authorities were ordered to hand over all the relevant information available in their archives. This explains why, in 75 years, there are hardly any documents found in local archives with information on these reburials.