The Turkish police arrested four members of a cell spying for France.
According to the police, the spy cell had been operating in Turkey since 2013.
It was headed by Metin Özdemir, a former Turkish military, who underwent intelligence training in France and was attached to the French Consulate General in Istanbul.
He was in charge of overseeing the Turkish far right and associations linked to Fettullah Gülen (banned after the 2015 coup).
The spies were in possession of fake MIT (Turkish Secret Service) cards and reported to two DGSE (French Secret Service) officers.
They received a salary of 600 euros per month.
The Franco-Turkish dispute is getting worse, as France continues to support the PKK (Kurdish terrorist organization); backs Greece in its oil claims and was recently involved in a collision with the Turkish navy off Libya.
France requested NATO to open an investigation into the incident.