A judge ejected one of Turkeys most respected investigative journalists from court Monday and ruled that he and three other suspects should remain in jail, in the controversial trial of staff from the main opposition newspaper.

It was one of the angriest exchanges so far in the trial on terror charges of 17 current and former writers, cartoonists and executives from Cumhuriyet ("Republic"), which has raised alarm over press freedom under President Recep Tayyip Erdogan.

The trial began on July 24, and after several conditional releases in previous hearings, four of the suspects remain behind bars.

The judge ordered the four of them -- investigative journalist Ahmet Sik, the paper's chairman Akin Atalay, editor-in-chief Murat Sabuncu and accountant Emre Iper -- to stay in jail, defence lawyer Kemal Aytac told AFP.

The next hearing will be on March 9 and take place in the Silivri prison complex, outside Istanbul, rather than the city's main courthouse where the trial has been heard until now.

'Judiciary controlled by government'

Earlier in the hearing, Sik was ordered to leave the court by the judge because of his "political" defence statement that condemned the government and claimed it treated its critics as "terrorists".

"There is a judiciary controlled by the government that is translating this 'terrorist' term into preposterous accusations," Sik, who has now been in prison for 360 days, told the court.

During the fraught hearing, Judge Abdurrahman Orkun Dag refused to allow Sik to continue.

"That's enough! If you want to play politics, become a member of parliament... I cannot allow him to defend himself like this. Take the defendant outside!" Dag said, ordering his removal.

Angry supporters in the courtroom responded by shouting: "You are all going to be tried one day" and "Ahmet will get out, he will write again" causing the trial to be adjourned for lunch.

Sik, already jailed from 2011-2012, wrote a book exposing former ties of members of the Turkish elite to the movement of US-based Islamic preacher Fethullah Gulen, who Ankara accuses of being behind last year's failed coup.

'Attempt to silence'

The 17 current and former Cumhuriyet employees are charged with supporting through their coverage three organisations Turkey views as terror groups -- the Kurdistan Workers' Party (PKK), the ultra-left Revolutionary People's Liberation Party-Front (DHKP-C), and the Gulen movement.

They face up to 43 years in prison if convicted.

Their supporters say the charges are absurd and the daily says the trial is an attempt to silence one of the last independent newspapers in Turkey.

Cumhuriyet is fiercely critical of Erdogan and has run front page stories that have angered the president.

"This trial is a symbol of the attempt to silence freedom of expression in Turkey. It is a symbol of pressure on journalists,"Gulendam San Karabulutlar, a defence lawyer, told AFP.

Dozens of supporters gathered outside the court in Istanbul, holding signs saying "You are not alone, we are not alone", "Justice for all" and "Freedom for all journalists".

Some held Monday's issue of Cumhuriyet whose front page read: "Justice immediately".

Some of the most high-profile suspects -- including political commentator Kadri Gursel -- have already been released but remain charged and on trial.

Dozens of journalists have been arrested in Turkey since the failed coup as part of its crackdown on alleged threats to the state. In total, more than 55,000 people have been arrested, raising concern in Western capitals.

According to the P24 press freedom group, there are 170 journalists behind bars in Turkey, most of whom were arrested under the state of emergency in place since July 2016.

Turkey is ranked 151st of 180 countries in the 2016 World Press Freedom index published by Reporters Without Borders (RSF).