Last week demands for hundreds of euros from tax authorities in the German state of Brandenburg began to land on the doormats of surviving "dwangarbeiders" or their widows.
"It hits me not only financially but emotionally," Simone De Vos, 84, the widow of a forced labourer told the Gazet Van Antwerpen.
"My late husband had anxiety attacks for decades after his time in Germany. It is outrageous that the Germans now want money back."
According to media reports in Belgium, the German authorities last year passed a law stating that pensions for former slave labourers would be taxed at the rate of 17 per cent.
The tax has been applied retroactively from 2005 meaning those Belgian survivors of Nazism or their widows awarded pensions by Germany as a form compensation now face large bills.