Founded in February 2013, the AfD focuses on so-called "soft" Euroscepticism, generally supporting Germany's membership in the European Union but slamming further European integration, unchecked immigration and the existence of the euro.
He has now apparently stepped down from the legislative committee in Brandenburg after converting to Islam.
Kalbitz told CNN that he only learned about Wagner's conversion in a telephone conversation with him a few days later.
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Wagner worked as an interpreter in a welcoming committee for refugees while serving as a member of AfD, mainly working with Muslim Chechens.
AfD spokesman Daniel Friese said that Wagner resigned for personal reasons and that the party "has no problem" with the fact that Wagner became a Muslim.
According to the AfD, it states that "Islam does not belong to Germany" and "Islamic culture do not blend well in Germany".
An anti-immigration and anti-Muslim political party in Germany just saw one of its own more prominent members leave the party and convert to Islam.More news: Don't let Aussie flu get the better of you
The party said it stood for the constitutional right of religious freedom, regardless of Wagner's conversion. "I also do not think it is a problem for the majority in the party". It is now the largest opposition party in Parliament, with the two biggest parties - the Christian Democrats and the Social Democrats - again looking to form a coalition. Its political manifesto also includes various anti-Islam references.
"The growing Islamisation of Germany poses an urgent challenge for its public and state order, cultural identity and the internal peace of our country", Gauland said. He left the party on January 11, AfD chairman Andreas Kalbitz wrote in a, adding the decision came as a surprise.
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