Ahmet Muhsin Tüzer, the "rocking imam" from the southern province of Antalya whose group "Firock" grabbed media attention last year, had been invited by the Serralves Museum in Porto to perform at an event in April.
Tüzer's band had previously performed concerts in Turkey and the United States, but this time the Diyanet had a change of heart after initially granting permission for the imam to perform in Portugal.
The eventual refusal came after the Culture Ministry had approved granting Tüzer financial support for the trip.
Tüzer told reporters that the situation would be "inexplicable" to event planners in Porto and was a "missed publicity opportunity."
"An important publicity opportunity has been missed at a time when Turkish tourism is suffering due to [outlawed Kurdistan Workers' Party] PKK terrorism and the war in Syria," he said, adding that the concert would help improve the image of Islam abroad at a time of rising Islamophobia.
"It could have transformed the dark image of Islam to a peaceful image. I was going to introduce Eastern culture to Westerners" Tüzer said, urging Diyanet head Mehmet Görmez to reconsider the refusal.
The imam also said he was willing to pursue legal means in order to challenge the Diyanet's decision.
"The Culture Ministry had decided to support the concert because it would help introduce our country's cultural activities abroad. It is now up to our administrators to weigh up the Diyanet's refusal" he added.
(Photo) - Antalya