Chairwoman Frauke Petry delivers a speech during the AfD party congress last November | Nigel Treblin/Getty Images German intelligence monitors far-right politicians: media report Baden-Württemberg wants checks on party members following anti-Semitism remarks.

Politicians of the German far-right party Alternative for Germany (AfD) are being monitored by the intelligence service, according to a report in the Frankfurter Allgemeine Sonntagszeitung newspaper.

Thomas Strobl, the interior minister of the German state of Baden-Württemberg has called for the surveillance of the AfD leaders following a row over anti-Semitic remarks that split the regional AfD fraction.

One of the party members, Wolfgang Gedeon who was elected to the regional parliament in March, compared Holocaust deniers to Chinese dissidents in a book that was published in 2012. His remarks caused an uproar when Gedeon became a Baden-Württemberg lawmaker of the AfD, now the third largest party in the state parliament.

“The intelligence service must keep a close eye on the AfD and individuals from that party," Strobl said. "If conditions for observation are present, we must act."

Statements of leading AfD politicians are the focus of a test that checks whether "the AfD wants to restrict or abolish the free democratic basic order as a whole or partially," according to a statement by the Stuttgart secret service.

In some federal states, in Bavaria for example, AfD politicians are already under survaillance.

The head of the Bavarian intelligence service said his office has found connections between individuals and the right-wing and Islamophobic groups, such as Pegida or the far-right Identitarian youth movement.