Plans for a major German exhibition documenting the way the Nazis used trains to send thousands of Jewish children to the gas chambers have been blocked by the head of the state-owned rail network. That has provoked a furious row with Chancellor Angela Merkel's government.

The exhibition, "11,000 Jewish children - with the Reichsbahn to death", was conceived by the German Nazi-hunter Beate Klarsfeld. It has already been shown at railway stations through France where its display of identity cards and other items belonging to child Holocaust victims received wide acclaim.

But plans to mount the exhibition at railway stations in Germany next year to coincide with the anniversary of the liberation of the Auschwitz death camp have been rejected by Hartmut Mehdorn, chief executive of Deutsche Bahn, the successor organisation to the Reichsbahn rail company. He is said to have cited "technical, organisational and financial reasons" for his refusal, despite the government's insistence that the exhibition must be shown at German railway stations.