Several countries accused in an American State Department report of wartime dealings with Nazi Germany during the Second World War have said they have nothing to fear from an investigation.

The report, released on Tuesday, said neutral countries, including Sweden, Portugal, Spain, Turkey and Argentina, had provided the Nazis with raw materials which were essential for its war effort and been paid in gold stolen from Holocaust victims.

Portugal, Spain and Turkey rejected the allegations, saying there had been no secrets and no wrongdoing in their dealings with the Nazis.

Switzerland welcomed the findings, saying it could lead to a more objective discussion of its role during the war.