A Turkish court on Tuesday ruled to keep in jail four staff from Turkey's main opposition daily on terror-related charges, in a hugely controversial case seen as a test for media freedom under President Recep Tayyip Erdogan.

Prosecutors accuse a total of 17 current and former writers, cartoonists and executives from Cumhuriyet ("Republic") of supporting terror groups, charges lambasted by the defence as absurd.

Four of the suspects remained behind bars ahead of Tuesday's latest hearing, with the others now free but still on trial and risking heavy jail sentences if convicted.

The Istanbul criminal court ruled that the four should stay in jail, dashing the hopes of supporters that all the accused could be released ahead of the verdict. The next hearing was set for December 25.

Dozens of supporters had earlier gathered outside the court in Istanbul, unfurling banners saying: "Stop hunting the opposition and arresting journalists" and "justice for Cumhuriyet".

The 17 are charged with supporting through their coverage three groups Turkey views as terror groups -- the Kurdistan Workers' Party (PKK), the ultra-left Revolutionary People's Liberation Party-Front (DHKP-C), and the movement of preacher Fethullah Gulen, blamed by Ankara for last year's failed coup.

The defendants risk up to 43 years in prison if convicted.

- 'Never bow to pressure' -

The court in July freed seven of the daily's staff after 271 days behind bars, including respected cartoonist Musa Kart and Turhan Gunay, editor of the books supplement.

Another defendant, one of Turkey's most respected journalists Kadri Gursel, was released last month after spending nearly a year in jail.

But the four who must remain behind bars for at least another two months include some of the biggest names in the Turkish media world.

The paper's chairman Akin Atalay and editor-in-chief Murat Sabuncu have now been held for 366 days while investigative reporter Ahmet Sik has been held for 305 days.

The fourth man, accountant Emre Iper, has been detained for 208 days, and must also remain under arrest.

Sik wrote a book exposing the past ties of members of the Turkish elite to the Gulen movement and has angrily denounced Erdogan and his allies at every opportunity in the court.

Addressing the court, Sabuncu vowed Cumhuriyet had not "bowed to pressure and will never do so". Atalay said their "arrest is not based on any legal grounds but a political plan".

"There is no crime, there is no proof and there is no release," the paper wrote bitterly after the ruling was announced.

- Releases in separate case -

The trial also resumed Tuesday of celebrated Turkish novelist Asli Erdogan in which she is accused of "terror propaganda" for the PKK on account of her work to the now shut down pro-Kurdish newspaper Ozgur Gundem.

The court ordered its news editor Inan Kizilkaya and the newspaper's licence holder Kemal Sancili to be released on judicial supervision after they were imprisoned for over a year, lawyer Erdal Dogan told AFP.

Erdogan -- no relation of the president -- faces life in prison if convicted but was released from pre-trial detention in December last year. She did not attend the hearing.

According to the P24 press freedom group, there are 170 journalists behind bars in Turkey, most of whom were arrested after the coup bid. Turkey ranks 155 out of 180 on the latest Reporters Without Borders (RSF) world press freedom index.

Since last July's coup bid, over 50,000 people have been arrested during the state of emergency over alleged Gulen links but opposition media and pro-Kurdish activists have also been caught up in the crackdown. Gulen denies any links to the coup bid.

An Istanbul court last week had ordered the conditional release of eight human rights activists, including Amnesty International's Turkey director Idil Eser, as their trial on contested terror charges continues.

Source: AFP