A diplomatic row has broken out in Turkey after the National Ministry of Education reportedly banned German teachers from encouraging the celebration of Christmas at Istanbul High School.

The dispute was prompted by an email sent to some 35 German teachers at the school, known locally as Erkek Lisesi. The email read: "No more Christmas celebration and/or lessons on Christmas including carol singing is permitted, effective immediately".

World Watch Monitor (WWM) observed: "That Turkey is the homeland of the real 'Santa Claus' is an irony largely lost on most media: St Nicholas, who secretly left gifts for poor children, was in fact Bishop Nicholas who lived in c.300 AD in Demre (formerly known as Myra), in Lycia, Southern Turkey."

WWM added: "Church history teaches that Nicholas attended the Council of Nicaea, close to Istanbul, where 300 early Church Fathers agreed on their core beliefs as followers of Jesus Christ. It's the teaching of these beliefs that now appears to be being challenged."

The German broadcast outlet Deutsche Welle (DW) reported that the school's management denied that they had banned celebrating Christmas. But DW also added the school said that German teachers have recently been "talking about Christmas and Christianity in a way that was not foreseen by the curriculum".

Online outlet Diken quoted the head of the commission for the new Turkish Constitution and ruling party AKP MP Mustafa Sentop as saying: "We will not allow missionising/proselytising in a government institution."

On December 18, after the case was reported in the German media, the Turkish-run school posted a statement on its website denying it had issued such a ban. It also claimed that a concert scheduled at the German consulate had been "cancelled by the German teachers in question without explanation".

WWM said that "it appeared by 19 December that Turkey was trying to say that the email's content ('nothing that is in the spirit of Christmas traditions and the Christian holiday should be announced, prepared or carried out in the classrooms from now on') had been misunderstood. The school is reported to have said that some German teachers had addressed Christmas without answering students' questions satisfactorily."

German Foreign Ministry spokesman Martin Schaefer said yesterday that he was confident what he called "misunderstandings" could be resolved.

On Saturday the German Foreign Ministry had declared: "We do not understand the surprising decision of the leadership of Istanbul Lisesi," adding: "It is a great pity that the good tradition of the inter-cultural exchange in the pre-Christmas period was suspended at a school with a long history of German-Turkish friendship."

Since 1884, the selective bilingual state school has provided Turkish students with high quality, free tuition in Turkish and German.

According to WWM, the high school has forbidden its 35 German teachers from speaking to the media about the controversy.