Saudi authorities have arrested the Turkish military attache to Kuwait during a stopover in the kingdom, Saudi-owned broadcaster Al Arabia reported late Sunday.
His arrest came in response to a request from the Turkish government, Al Arabiya said, citing Saudi sources.
The diplomat was arrested at the Dammam airport in eastern Saudi Arabia while he was trying to travel to Dusseldorf, Germany, the broadcaster said without details.
There was no official Saudi comment.
Turkish President Recep Tayyip Erdogan vowed Sunday that the "cleansing" of state institutions will continue after a failed coup attempt, with 6,000 people already detained in Turkey.