Child care authorities in Aarhus feared that a 15-year-old Muslim boy's father might persuade him to travel to Syria to fight with Islamic extremists and placed him into care in September, Jyllands-Posten reported.
The paper said the local authorities forced the boy into a juvenile home after it emerged that he had begun to attend Grimhøj Mosque, notorious for refusing to denounce the terror group Isis and long suspected of radicalizing area youth.
"You cannot force a lone child into care due to a suspicion of radicalisation," the father's lawyer Tage Goettsche told Berlingske.
Researchers told local media the move was heavy-handed and that a juvenile home might radicalize the boy further through interaction with young criminals.
"You'd typically try to find a foster home," social scientist Hanne Hartoft at Aalborg University told news agency Ritzau.
By late last year Aarhus -- a city of only 324,000 residents -- sent as many as 30 people to fight in Syria. East Jutland Police have previously said that at least two dozen of the some 110 individuals who have left Denmark to fight in Syria have come from Grimhøj Mosque.
Measured per capita, Denmark is the second largest European source after Belgium of jihadist fighters going to the Middle East.
Just last week, German officials said they would charge Grimhøj Mosque imam Abu Bilal Ismail with incitement of hatred for anti-Semitic remarks he made in Berlin last summer.
The mosque was also the subject of a documentary from broadcaster DR last month, in which mosque leaders said that they want to see an Islamic caliphate established, that they don’t believe in democracy and that a Danish convert who carried out a suicide bomb attack in Iraq is a hero.
Following that documentary, the mosque requested police assistance after receiving a number of threats.
Two week after that, Grimhøj Mosque received rare praise from police and Aarhus authorities, who said that the mosque’s leaders have helped to slow the stream of Danish Muslims who travel to Syria as foreign fighters.