The Turkish Customs and Trade Ministry said on April 30 that the man was detained in the city of Zonguldak, on Turkey's Black Sea coast, following a search of his truck after it arrived by boat from Ukraine, RFE/RL reported.

Read alsoAustrian suspected of killings in Donbas detained on Polish border - Radio PolandThe ministry said in a statement that documents officially listed diapers as the truck's cargo, but that the vehicle was actually carrying the "main" components of two Russian-made antitank missile systems used by armed groups, including Islamic State militants and Kurdish rebels.

The suspect, identified by the ministry by his initials – E.E. – was detained on April 27, and a court subsequently ordered him to remain in custody, authorities said.