According to police, a close aide of ISIS leader Abu Bakr Al Baghdadi was apprehended in Istanbul on Sunday.
According to Istanbul police, the Afghan national, known only by the codename Basim, was apprehended in the Atasehir district on the city's Asian side on Wednesday.
According to reports from the joint operation with Turkey's intelligence service, the perpetrator assisted Al Baghdadi in hiding in Syria's Idlib province after ISIS was defeated in 2019.
In October 2019, US special forces raided Al Baghdadi's Syrian hideout and killed him.
Following the detention, Turkish media released a photo of a balding, bearded man in a flight suit and an earlier photo of a long-haired, heavily bearded man holding a curved sword in military fatigues.
According to the Demiroren news agency, Basim was accused of organizing ISIS training and sitting on its decision-making council while in Syria and Iraq.
According to the department, he entered Turkey with a fake passport and identification card.
Turkey detains ISIS suspects regularly, with many of them suspected of plotting attacks in the region.