Ankara tries to maintain control over Turkish imams abroad but Germans are suspicious.

Turkish Muslims are the largest immigrant group in Germany and almost four million Germans go to Turkey each year as tourists. In theory, this should be a great relationship, however, fellow citizens of Islamic faith are viewed with suspicion.

And since Turkey's election of Islamic-conservative Prime Minister Erdogan, there have been speculations about the activities of imams and preachers sent by Turkey to the German mosques.

Report: Susanne Güsten / Eva Wutke