* Graft probe gives an opportunity for browbeaten media
* Previously taboo, corruption makes the front pages
* Business interests keep mainstream media cowed
* Journalists fear dismissal, detention
By Dasha Afanasieva
ISTANBUL, Feb 3 (Reuters) - Dozens of their colleagues are in prison or on trial, thousands of faceless opponents hound them on Twitter, and phone calls from government officials warn them over their coverage - all hazards of the trade for Turkey's journalists.
Government critics who refuse to be muzzled can find themselves sacked. Others avoid trouble, such as the broadcaster which screened a documentary on penguins last June while police sprayed thousands of demonstrators in Istanbul with tear gas.
What has erupted in the past few weeks - a probe into alleged corruption at the heart of Prime Minister Tayyip Erdogan's government - might seem like a gift to Turkey's cowed and long-suffering press.
But, with a few exceptions, much of the press is in no position to capitalise on the scandal by taking a more robust line with the government.
The scandal has blown open a feud between Erdogan and the U.S.-based cleric Fethullah Gulen, a powerful former ally whose "Hizmet" (Service) movement has influence in the police and judiciary, as well as parts of the media, and whom Erdogan blames for orchestrating the graft probe to unseat him.
"Gulenist" newspapers such as Zaman and Bugun, previously loosely allied to Erdogan's AK Party, have reported details of the allegations, from pictures of cash stuffed in shoe boxes to damaging phone recordings between businessmen and Erdogan's associates, something almost unthinkable just a few months ago.
Pro-government newspapers like Sabah, Star and Yeni Safak have largely portrayed the corruption investigations as a plot against Erdogan.
In the middle is a mainstream media, largely owned by sprawling conglomerates with business ties to the state, which has been cautiously trying to find a more assertive new voice, although its ownership structures cast doubt over whether there can be real change.
"The graft probe is a new opportunity for Turkish journalism to push itself out of suffocation," said Yavuz Baydar, one of Turkey's most prominent journalists who launched Platform 24, a media monitoring website, on Monday.
"The question is whether major, conglomerate-owned outlets such as Hurriyet and Milliyet will be able to rise up to the challenge," he told Reuters. Milliyet declined to comment while the editor in chief of Hurriyet did not respond to emailed requests.
Baydar lost his job at Sabah, whose former owner Calik Holding is run by Erdogan's son-in-law, after criticising the police crackdown on anti-government protests last June.
Sabah was sold in December to Kalyon, a construction group with major government contracts, in a deal that typifies the ownership structures in Turkey's media landscape.
At least a dozen newspapers and 10 TV stations are owned by conglomerates with energy, construction or mining interests, all sectors heavily dependent on government business.
"This has created a situation in which media outlets are used to promote the ownership group's financial interests," U.S.-based press watchdog Freedom House said in a report published on Monday.
"Members of the media and the government alike describe newspapers' Ankara bureau chiefs as 'lobbyists' for their companies," it said.
Erdogan has described the corruption investigation as an attempted "judicial coup". He has reassigned prosecutors and judges and thousands of police officers.
That has brought the probe to a halt and prompted lawyers, despairing at what they view as a lack of transparent judicial process, to leak court documents to those parts of the press not favourable to the government.
But when news website T24 published an article about a parliamentary question from the opposition Republican People's Party regarding claims of bribery in the sale of Sabah and other media assets, it was told to take it down by the media regulator. Then on Monday the same regulator said it had sent the warning by mistake.
"We're just trying to provide something different from the 'government newspapers' that publish the AK Party line that this is a coup d'etat," said Erhan Basyurt, Bugun's editor-in-chief.
The paper's circulation went up to 165,000 from 140,000 in the month after the corruption probe broke.
Other newspapers have had to be more cautious.
A senior editor at one of Turkey's largest dailies, who did not want to be named and fears for his job after his boss was told to fire him, said he had been the subject of a hate campaign on the Internet and in pro-government newspapers.
He was followed and threatened, his car-license plate at one point published online, he said.
Sometimes he did not put bylines on stories to protect reporters. He also might soften the headline or put material damaging to Erdogan lower down in stories.
Restrictions on press freedom and attacks on journalists are nothing new in Turkey. Commemorations of the 2007 murder of Armenian-Turkish journalist Hrant Dink, widely viewed as a political assassination, still draw tens of thousands each year.
But the taboos have changed.
Where once criticism of Mustafa Kemal Ataturk, the revered founder of the modern secular republic, or portraying Kurdish militants as anything other than "terrorists" might have resulted in a jail sentence for "insulting Turkish identity," now it is criticism of the government which is problematic.
Editors and reporters said they had received phone calls from officials close to the prime minister asking them to change their coverage or dismiss journalists for critical stories.
"The voice on the end of the line says, 'Beyefendi rahatsz olmasn,' which can be translated as 'Better not upset sir'," said prominent author and columnist Ece Temelkuran, fired from the Haberturk newspaper after a series of such warnings for her coverage of a Turkish air strike which killed Kurdish civilians.
"The use of the word 'sir', 'beyefendi' makes your realise straight away what you are dealing with," she said.
Government and AK Party officials declined to comment.
Turkey is the world's leading jailer of journalists, with 40 in prison as of December, according to the Committee to Protect Journalists. Reporters Without Borders' press freedom index ranks Turkey 154th out of 178.
The government says no journalist is being held or tried for their work.
"They are facing situations like these solely because they have got mixed up in other activities," a senior government official, who did not want to be names, told Reuters.
But government influence, such as the indirect sackings and threat of loss of business for parent companies, which poses the main threat to press freedom, journalists and rights groups say.
"The government seems to have acquired the habit of shooting the messenger whenever it is in trouble. Journalists should not have to suffer because of high-level administrative in-fighting," Reporters Without Borders said in a December report.
These criticisms come ahead of local elections in March, a presidential race in August and parliamentary polls next year.
Opposition candidates complain that Erdogan's frequent speeches are broadcast live and in full by a slew of television stations, a degree of coverage his opponents do not enjoy.
"One of the most pernicious effects of the widespread firings of reporters and editors from the 'mainstream' media is that there are fewer moderate voices to be heard," Freedom House said in its report.