Bangladesh, Sept. 22 -- A belated investigation by Turkish authorities into a sprawling drug trafficking syndicate stretching from Iran to Western Europe has exposed how an Iranian trafficker acquired Turkish citizenship with apparent ease and emerged as a central figure in an international crime network.

The case, largely built on intelligence shared by European law enforcement, reveals a web of traffickers who for years used Turkey as a strategic hub to channel heroin into European markets via Russia and the Balkans.

At the center is Amir Alizadeh, an Iranian national who became known as Nihat Yılmaz after naturalization. Investigators allege that Alizadeh supplied hundreds of kilograms of heroin to the syndicate and laundered th...