Abu Raad, who works at the al-Rashideen mosque in the city of Gävle, was seized on Wednesday and and placed in a migration detention centre along with his adult son.
“We want to know the reason for this. We don't know anything,” Mohammad al-Najjar, the mosque's leader, told Sweden's TT news wire. He said he was hoping to be able to make contact with Raad over the weekend through his lawyer.
According to Doku, which investigates Islamic extremists in Sweden, Raad has inspired many Islamic State sympathisers, has hailed an IS victory in Iraq, and has called for homosexual men to be executed.
Raad's relatives on Thursday circulated a petition claiming that he was facing deportation, and would face “a guaranteed death sentence” if he ever returned to Iraq.
”After a full 23 years in Sweden, it has been decided Gävle mosque's imam Abo Raad should be deported from Sweden together with his son,” the petition read.
“No concrete reason has been given for the deportation, and it is a scandal that the Swedish state is choosing to deport someone who has contributed so greatly to society and the Muslim community both locally in Gävle and in Sweden as a whole.”
On the mosque's website, there is a speech Raad gave to an inter-denominational meeting, in which he says that Islam “condemns extremism”.
According to Swedish law, Säpo can deport anyone who is not a Swedish citizen who is seen as a threat to Swedish security. Sweden's security police Säpo refused to comment on Raad's case.