Christian refugees are exposed to "brutal harassment" in German camps, an Orthodox priest has warned.

Hegumen Daniil, a superior of the St George the Victorious Monastery in Gotschendorf, Germany, joined a number of other leaders who have spoken of the treatment Christians receive in refugee camps.

"Christian refugees from Syria, Eritrea and other countries are exposed to humiliation, manhunt and brutal harassment at the camps for refugees by Muslim neighbours," Daniil said in a letter to Federal Minister for Special Affairs and Head of the German Federal Chancellery, Peter Altmaier.

"The cases when humiliation comes to injuries and threats of death are frequent," he added.

Christians who have converted from Islam are at particular risk, he said, and many have taken to sleeping outside the camps for fear of violence.

"Many Christians who came from the Middle East are suffering from such a strong harassment that they want to come back home, because their situation there seems to them a lesser evil as compared to the circumstances at German refugee accommodation centers," said the priest.

He called on the authorities to ensure police intervene to protect at-risk minorities such as Chrisians and Yazidis in refugee camps.

"We ask you to exert the necessary pressure to ensure the observation of the German legislation at the German centers for asylum seekers and until this is impossible to fully implement this to accept the proposals by the clergy of different Christian confessions in Germany and ensure so that the Christians will be accommodated separately from the Muslims," reads the letter.

The priest's comments follow the number of women filing criminal complaints of sexual harrassment on New Years Eve in Cologne topping 500. An official report has suggested the suspected perpetrators are "almost exclusively" from a migrant background.