ISTANBUL (Reuters) - A French photographer detained two weeks ago by Turkish police while on assignment in the mainly Kurdish southeast has begun a hunger strike to protest against his detention, a press activism group said on Wednesday, citing his lawyer.

Istanbul-based freelance journalist Mathias Depardon was taken into custody by police in Batman province on May 8 and has been held at a deportation center in the border province of Gaziantep, Reporters Without Borders (RSF) said in a statement.

Citing Depardon’s lawyer, RSF said he started the hunger strike on Sunday. “The ordeal to which Matthias Depardon is being subjected is unacceptable and has lasted for too long,” said Johann Birr, the head of RSF’s Eastern Europe and Central Asia desk.

A Turkish official said Depardon “had not acted within the boundaries of journalistic principles,” without elaborating further or commenting on the report of the hunger strike.

In previous statements, RSF had cited police saying Depardon was arrested on suspicion of publishing “terrorist propaganda”, referring to his photographs in French media of militants from Kurdistan Workers Party (PKK), seen as a terrorist group by Turkey, the United States and the European Union.

Since last year’s abortive putsch, Turkish authorities have shut more than 130 media outlets, raising concerns about media freedom in a country that aspires to join the European Union.

Turkey is the biggest jailer of journalists globally, according to the rights group Committee to Protect Journalists (CPJ). Turkey’s Press Council, a representative body for Turkish journalists, says that 159 journalists are currently in jail in Turkey.

The country ranks 155th out of 180 countries in RSF’s World Press Freedom Index.

Turkey has also suspended or dismissed more than 150,000 judges, teachers, police and civil servants and has arrested nearly 50,000 suspected of links to the Gulen movement.

Two Turkish teachers removed from their jobs in the government crackdown after last July’s failed coup have been on hunger strike for more than two months. They were arrested on Tuesday.

Turkish officials say the Gulen movement had set up a “state within a state” that threatened national security. They point to the gravity of last July’s coup, when rogue troops commandeered warplanes to bomb parliament and used tanks to kill 240 people.

But Erdogan’s critics in Turkey and abroad say he is using the coup to purge opponents and muzzle dissent. Last month he narrowly won a referendum that granted him sweeping new powers.