ANKARA, Turkey (AP) — A leading advocate for press freedoms says a French photographer who was taken into custody in Turkey has started a hunger strike to protest his detention.

Reporters Without Borders, citing the photographer's lawyer, said Wednesday that Mathias Depardon, began his hunger strike on May 21.

The photographer, who was based in Turkey, was on assignment for the National Geographic magazine when he was detained in the mainly-Kurdish province of Batman on May 8. He was being held at a deportation center in the province of Gaziantep.

Turkish officials have not commented on the reasons for his detention.

Johann Bihr, the head of the group's Eastern Europe and Central Asia desk, said the "ordeal to which Mathias Depardon is being subjected is unacceptable and has lasted for too long."