UBS, the Union Bank of Switzerland, initially played down the significance of the armfuls of files rescued by Christoph Meili in January. It emphasised that the files had nothing to do with the question of dormant bank accounts, many of which are thought to belong to Jews who died in the Holocaust.
But it was confirmed yesterday that the files could prove useful to a major inquiry into Switzerland's dealings with the Nazis, because they covered the separate but related issue of property.
Linus von Castelmur, the secretary of the international Bergier commission of historians set up by the Swiss government, said yesterday the panel had found some of the documents relevant to its investigations. He would give no details.
Mr Meili realised the documents related to business dealings with Germany in the 1930s and 1940s. Under Swiss law, no documents relating to the period should be destroyed until they have been examined by the Bergier commission. He saved as many as he could and passed them to the Jewish community in Zurich. But his security company sacked him over the incident and he fled to America, as he faced possible prosecution for breaking Switzerland's banking secrecy rules.
The bank had released no details of what the files contained until yesterday, in the face of mounting public speculation.
A UBS spokeswoman said Mr Meili took a total of 65 property files and 47 of them related to the period before and during the war.
All were from a bank, the Eidgenossische Bank, which UBS took over in 1945. Any accounts were absorbed into UBS, but a number of properties the Eidgenossische Bank owned were dealt with separately. The rescued files covered these property transactions.
Among them were three properties where a German bank in 1937 acted as intermediary and whose previous owners were possibly Jews. During the 1930s, Jews came under Nazi pressure to sell their property in Germany at prices well below market values at that time.
In a statement, UBS said yesterday: "UBS would like to express once again how much it regrets the destruction of these documents, which was not a deliberate act on the part of the bodies responsible at UBS."
However, it also stressed that the information it released yesterday "in no way constitutes an opinion on the business activities of the Eidgenossische Bank in the Thirties and Forties". An assessment of the business conduct of the bank would be made by the Bergier commission. "UBS does not wish to prejudice this decision in any way."Reuse content