The Swiss Culture Office says museums need to intensify provenance research, in a report on looted art from the Nazi era.
It says access to the results of such research and to relevant archives has to be simplified.
The report said it was important that international declarations in the area of looted art be applied. There was a need to improve information and awareness at all levels in public and private museums.
It is based on a voluntary survey of 551 Swiss museums on the state of provenance research carried out between July 2008 and October 2010.
The document also includes the results of the Holocaust Era Assets Conference held in Prague in June 2009.
At the international level, Switzerland has signed the Washington Conference Principles on Nazi-Confiscated Art and adopted the Terezin Declaration on looted art.
The government, which commissioned the report, has called for continuing efforts to deal with the problem of looted art in a “transparent, legal and adequate” manner.