Reporters Without Borders has urged Turkey’s judicial system to reverse an Ankara court’s political and “totally disproportionate” decision on 25 November to ban media coverage of the questioning of four former ministers by a parliamentary commission that is investigating major corruption allegations.

Noting that coverage of this corruption story has repeatedly been obstructed ever since it broke nearly a year ago, triggering a political crisis, the RSF recalled that the grounds given for the gag order imposed by the Ankara magistrates’ court on 25 November were the need to protect the confidentiality of the investigation and the presumption of innocence.

The court accepted the need to “prevent any violation of the personal rights” of the four ex-ministers – Zafer Çağlayan, Muammer Güler, Egemen Bağiş and Erdoğan Bayraktar – and to “protect their reputation.”

After many delays, the commission finally began questioning the former ministers yesterday, when Bayraktar, the former environment and urban planning minister, appeared before the panel. Bağiş, the former European affairs minister, is to be questioned today.

“Defamation and violation of the presumption of innocence are already penalized under Turkish law and can be the subject of judicial proceedings if they are thought to have occurred,” said Johann Bihr, the head of the Reporters Without Borders Eastern Europe and central Asia desk.

“But banning any reference to this event in advance, even by means of images, constitutes unjustifiable censorship of media coverage. The public debate cannot overlook the fact that four former ministers are suspected of corruption, especially as this case has dominated Turkish politics for the past year.”

The story broke when police and judicial investigators questioned dozens of leading figures after carrying out a series of raids on 17 and 25 December 2013. Those detained for questioning included the sons of four ministers, the CEO of a state bank and a construction magnate.

The government reacted angrily to what is regarded as a plot by its former political allies in the Gülen fraternity, an influential religious movement with many members within the police and justice system.

Hundreds of police officers, inspectors, judges and prosecutors were fired during the following months, with the result that the investigation into one of the main aspects of the case was closed in October. Lack of action by the specially created parliamentary commission of enquiry led many commentators to conclude that its sole purpose was to allay suspicion of a cover-up.

The authorities have repeatedly obstructed media coverage of the case as it continued to dominate the public debate during the past year. Journalists have been fired, critical websites have been blocked and the intelligence services have been given broad powers to spy on the population.

The gag order issued on 25 November is effective until the scheduled end of the parliamentary enquiry on 27 December, which conveniently includes the two anniversaries of last December’s raids. An Istanbul criminal court already imposed a gag order in February on businessman Reza Zarrab’s role in the alleged corruption.

Gag orders are becoming more frequent and extensive in Turkey. One was imposed in June on Islamic State’s abduction of 80 Turkish citizens in Iraq. In January, one was imposed on mysterious trucks travelling to Syria that several media suspected were arm convoys organized by the Turkish intelligence services. A gag order was issued in May 2013 on the bombings in Reyhanli, on the Syrian border.

Turkey is ranked 154th out of 180 countries in the 2014 Reporters Without Borders press freedom index.