An unorthodox Muslim group in Germany said on Friday it was planning legal action and protests over an episode of a popular television series linking it to incest.
Three hundred members of the Alevi community gathered outside the studios of the state-funded ARD channel in Berlin on Thursday, claiming that it was slandered in an episode of the "Tatort" (Crime Scene) detective series broadcast on December 23.
It has called for a bigger demonstration in the western city of Cologne on Saturday.
The "Tatort" episode dealt with sexual abuse within an Alevi family in Germany and the murder of a daughter who wanted to go to the police.
The Alevi community in Berlin attempted unsuccessfully to stop the programme being shown under German laws banning incitement to racial hatred on the grounds that it revived age-old prejudices against the Alevis.
Alevis have been the subject of accusations of incest from Sunni Muslims over the centuries because they include women and children in their religious rituals.
The producers of the programme, NDR, which is part of ARD's regional network, rejected the legal challenge to it being shown as an attempt to restrict the freedom of the press.
But the city-state of Berlin has now said it will investigate the programme and the Alevi community has said it will file further legal complaints in other German states in the next few days.
Mehmet Ali Toprak, the general secretary of the Alevi community in Germany, told the Tageszeitung newspaper: "The Alevis respect the freedom of the press and freedom of opinion and are opposed to any ban on cultural expression. But these values must not be used to harm the dignity of a minority."
The director of the episode, Angelina Maccarone, said she had wanted to portray the difficulties of discussing incest and child abuse within immigrant communities in Germany, but admitted she had been unaware of the accusations made against Alevis.
"Despite extensive research, I did not know that there was an age-old prejudice against Alevis," she told the Tageszeitung.
Alevis, considered by some to be a sub-group of Shiite Islam, worship in assembly houses instead of mosques and allow women and men to pray together.
Around 20 percent of Muslims in Turkey are Alevis and the group also has a significant community in Syria.
Germany is home to more than two million Turks.