The national government must "demand that the German federal government end the pension scheme for these Belgians," lawmakers said, in a legislative text adopted on Tuesday.

Paying pensions for "collaboration in one of the most murderous regimes in history is in contradiction with collective remembrance" and against the values of the European Union, they said.

The pensions are sent monthly to residents of Belgium who volunteered to fight alongside the German army, as well as those forcibly recruited in the annexed territories of eastern Belgium, historian Christoph Brull of the University of Luxembourg told AFP.

The pensions are paid under a 1951 German law, which allows World War II war victims to receive a pension, he said.

The German Labour ministry told AFP that "in February 2019, a total of 18 people in Belgium were still receiving these benefits, which are paid out by the North Rhine-Westphalia regional government".

The ministry insisted none of the current beneficiaries in Belgium "are former members of the Waffen-SS", the Nazi force held responsible for some of the Third Reich's worst atrocities.

"They may be Belgian nationals or, for example, German nationals who have settled in Belgium," the ministry said.

According to the historian Brull, only people with disabilities who have not been convicted of war crimes can today benefit, but "there is a grey area", he added.

"The disability criteria are quite open and the certainty of who did what (in the war) remains unclear," he added.

World War II remembrance group "Memoire-Herinnering", which has raised awareness of the scheme, says some beneficiaries even received full salaries several years after the end of the war.

"Germany considered that it should ensure the commitments of the Third Reich and resumed payments," said the association's Alvin De Coninck, who has been working on the subject for seven years.

Lawmakers insisted that the Belgian government request from Germany "all information needed" to clear up the matter and launch an investigation.