Records about stolen artworks taken during World War II are to be placed on an international database so items can be traced.
It is hoped publishing the documents online will help families and historians find missing items seized by the Nazis.
The National Archives and the Commission for Looted Art have signed an agreement to provide the documents.
The files, dated between 1939 and 1961, feature inventories and images of art.
The records also include details about efforts to identify and recover the articles during and after World War II.
"By digitising and linking archival records online, researchers will be able to piece together the stories of what became of cultural objects," said Oliver Morley. chief executive and keeper of the National Archives.
Last year the Leopold museum in Austria agreed to pay a Jewish art dealer's estate $19m (£11.5m) for an Egon Schiele painting, Portrait of Wally, that the Nazis had stolen from her.
The museum has now announced it will sell another of the artist's works to pay off a loan it took out to cover the costs of a 12-year legal battle.
